Online Etymology Dictionary

connective (adj.): 1650s, from connect + -ive (if from Latin, it likely would have been *connexive). Connective tissue is from 1839.
connectivity (n.): 1872, from connective + -ity.
connector (n.): 1795, "tube for connecting other materials," agent noun in Latin form from connect and usefully distinct from connecter.
connexion (n.): see connection; also see -xion.
conniption (n.): 1833, American English, origin uncertain; perhaps related to corruption, which was used in a sense of "anger" from 1799, or from English dialectal canapshus "ill-tempered, captious," probably a corruption of captious.
connivance (n.): the main modern form of connivence (q.v.).
connive (v.): c. 1600, from Latin connivere, also conivere "to wink," hence, "to wink at (a crime), be secretly privy," from com- "together" (see com-) + base akin to nictare "to wink," from PIE root *kneigwh- (see nictitate). Related: Connived; conniving.
connivence (n.): 1590s, from Latin conniventia, from conniventem (nominative connivens), present participle of connivere (see connive). Spelling with -a- prevailed after early 18c., but is unetymological.
connivent (adj.): 1640s, from Latin conniventem (nominative connivens), present participle of connivere (see connive).
conniving (adj.): 1783, present participle adjective from connive. Earlier in this sense was connivent.
connoisseur (n.): 1714, from French connoisseur (Modern French connaiseur), from Old French conoisseor "an expert, a judge, one well-versed," from conoistre "to know," from Latin cognoscere "to get to know, recognize, become well-acquainted with," from com- "with" (see com-) + gnoscere "recognize" (see notice (v.)).
Connor: masc. proper name, little used in U.S. before 1980; in the top 100 names given to boys from 1992; apparently an alteration and appropriation of the surname Conner (13c.), representing Old English cunnere "examiner, inspector" (as in ale-conner (see con (n.2)).
connotate (v.): 1590s, from Medieval Latin connotatus, past participle of connotare (see connote). Obsolete; replaced by connote.
connotation (n.): 1530s, from Medieval Latin connotationem (nominative connotatio), from connotat-, past participle stem of connotare "signify in addition to the main meaning," a term in logic, literally "to mark along with," from Latin com- "together" (see com-) + notare "to mark" (see note).

A word denotes its primary meaning, its barest adequate definition -- father denotes "one that has begotten." A word connotes the attributes commonly associated with it -- father connotes "male sex, prior existence, greater experience, affection, guidance."
connote (v.): 1660s, from Medieval Latin connotare "to mark along with," (see connotation). A common word in medieval logic. Related: Connoted; connoting.
connubial (adj.): 1650s, from Latin connubialis, variant of conubialis "pertaining to wedlock," from conubium "marriage," from com- "together" (see com-) + nubere "to wed" (see nuptial).
conquer (v.): c. 1200, cunquearen, from Old French conquerre "conquer, defeat, vanquish," from Vulgar Latin *conquaerere (for Latin conquirere) "to search for, procure by effort, win," from Latin com-, intensive prefix (see com-), + quaerere "to seek, gain" (see query (v.)). Related: Conquered; conquering.
conquerer (n.): obsolete form of conqueror; see -er.
conqueror (n.): c. 1300, from Anglo-French conquerour, Old French conquereor, from Old French conquerre (see conquer). Another early form was conquestor. William the Conqueror so called from early 12c. in Anglo-Latin: Guillelmus Magus id est conquæstor rex Anglorum.
conquest (n.): early 14c., a merged word from Old French conquest "acquisition" (Modern French conquêt), and Old French conqueste "conquest, acquisition" (Modern French conquête), both from past participle of conquerre, from Vulgar Latin *conquaerere (see conquer).
conquistador (n.): 1830, from Spanish conquistador, literally "conqueror," noun of action from conquistar "to conquer," from Vulgar Latin conquistare, from Latin conquistus, past participle of conquirere "to seek for" (see conquer).
Conrad: masc. proper name, from Old High German Kuonrat, literally "bold in counsel," from kuon "bold" + rat "counsel" (see read (v.)).
consanguine (adj.): c. 1600, from French consanguin (14c.), from Latin consanguineus "of the same blood" (see consanguinity).
consanguineous (adj.): c. 1600, from Latin consanguineus "of the same blood" (see consanguinity).
consanguinity (n.): c. 1400, from Middle French consanguinité, from Latin consanguinitatem (nominative consanguinitas), from consanguineus "consanguineous, of the same blood," from com- "together" (see com-) + sanguineus "of blood" (see sanguine).
conscience (n.): early 13c., from Old French conscience "conscience, innermost thoughts, desires, intentions; feelings" (12c.), from Latin conscientia "knowledge within oneself, sense of right, a moral sense," from conscientem (nominative consciens), present participle of conscire "be (mutually) aware," from com- "with," or "thoroughly" (see com-) + scire "to know" (see science).

Probably a loan-translation of Greek syneidesis, literally "with-knowledge." Sometimes nativized in Old English/Middle English as inwit. Russian also uses a loan-translation, so-vest, "conscience," literally "with-knowledge."
conscient (adj.): c. 1600, "conscious," from Latin conscientem, present participle of conscire "to be conscious" (see conscience). Also with meaning "a conscious being" (c. 1770).
conscientious (adj.): 1610s, from Middle French conscientieux (16c.; Modern French consciencieux), from Medieval Latin conscientiosus, from conscientia (see conscience). Related: Conscientiously; conscientiousness.
conscientious objector (n.): 1896, in reference to those with religious scruples about mandatory vaccination. Military sense predominated from World War I.
After a chequered career full of startling episodes and reversals, the Vaccination Bill becomes virtually the Vaccination Act. In Parliament the hottest of the contest centred round the conscientious objector. [The Lancet, Aug. 13, 1898]
conscionable (adj.): 1540s, from conscioned "having a conscience" (from conscience) + -able; obsolete from early 18c. but fossilized in its negative, unconscionable.
conscious (adj.): c. 1600, "knowing, privy to," from Latin conscius "knowing, aware," from conscire (see conscience); probably a loan-translation of Greek syneidos. Sense of "active and awake" is from 1837.
consciousness (n.): 1630s, "internal knowledge," from conscious + -ness. Meaning "state of being aware" is from 1746.
conscript (n.): 1800, perhaps a back-formation (influenced by French adjective conscrit) from conscription.
conscript (adj.): 1530s, from Latin conscriptus, past participle of conscribere "to draw up, list," literally "to write together" (see conscription).
conscript (v.): 1813, American English, from conscript (n.). A word from the militia drafts in the War of 1812. Popularized (or unpopularized) during U.S. Civil War, when both sides resorted to it in 1862. Related: Conscripted; conscripting.
conscription (n.): late 14c., "a putting in writing," from Middle French conscription, from Latin conscriptionem (nominative conscriptio) "a drawing up of a list, enrollment, a levying of soldiers," from conscribere "to enroll," from com- "with" (see com-) + scribere "to write" (see script (n.)).

Meaning "enlistment of soldiers" is from 1520s; the sense "compulsory enlistment for military service" (1800) is traceable to the French Republic act of Sept. 5, 1798. Technically, a conscription is the enrollment of a fixed number by lot, with options of providing a substitute.
consecrate (v.): late 14c., from Latin consecratus, past participle of consecrare "to make holy, devote," from com- "together" (see com-) + sacrare (see sacred). Related: Consecrated; consecrating.
consecration (n.): late 14c., from Latin consecrationem (nominative consecratio), noun of action from consecrat-, past participle stem of consecrare (see consecrate).
consecutive (adj.): 1610s, from French consécutif (16c.), from Medieval Latin consecutivus, from Latin consecutus "following closely," past participle of consequi (see consequence). Related: Consecutively.
consensual (adj.): 1754, "having to do with consent," from stem of Latin consensus (see consensus) + -al (1). Meaning "by consent" is attested from 1800.
consensus (n.): 1854 as a term in physiology; 1861 of persons; from Latin consensus "agreement, accord," past participle of consentire (see consent (v.)). There is an isolated instance of the word from 1633.
consent (v.): early 13c., from Old French consentir (12c.) "agree, comply," from Latin consentire "feel together," from com- "with" (see com-) + sentire "to feel" (see sense (n.)). "Feeling together," hence, "agreeing, giving permission," apparently a sense evolution that took place in French before the word reached English. Related: Consented; consenting.
consent (n.): c. 1300, "approval," also "agreement in sentiment, harmony," from Old French consente, from consentir (see consent (v.)). Age of consent is attested from 1809.
consequence (n.): late 14c., "inference, conclusion," from Old French consequence "result" (13c., Modern French conséquence), from Latin consequentia, from consequentem (nominative consequens), present participle of consequi "to follow after," from com- "with" (see com-) + sequi "to follow" (see sequel). Sense of "importance" (c. 1600) is from notion of being "pregnant with consequences."
consequences (n.): see consequence. As the name of a round game, attested from 1796.
consequent (adj.): late 14c., in various senses now restricted to consequence, from Middle French conséquent "following, resulting," from Latin consequentem (nominative consequens); see consequence. Meaning "an event which follows another" is from 1610s. Mathematical sense is from 1560s. Related: Consequently.
consequential (adj.): 1620s, from consequent (Latin consequentia) + -al (1). Meaning "pregnant with consequences, important" is recorded from 1728. Related: Consequentially (c. 1600).
consequentialism (n.): 1969, from consequential + -ism. The philosophy that the morality of an action is to be judged solely by its consequences. Related: Consequentialist.
conservancy (n.): 1755, "commission with jurisdiction over a port or river," from Latin conservant-, present participle stem of conservare (see conserve) + -cy. Earlier was conservacy (mid-15c., Anglo-French conservacie). Meaning "official preservation of undeveloped land" dates from 1859 (first reference is to protection of bo trees in Ceylon).
conservation (n.): late 14c., conservacioun, "preservation of one's health and soundness," from Latin conservationem (nominative conservatio) "a keeping, preserving, conserving," noun of action from past participle stem of conservare (see conserve). Meaning "preservation of existing conditions" in any sense is from mid-15c. Since late 15c., in reference to English municipal authorities who had charge of rivers, sewers, forests, fisheries, etc. Specifically of the environment from 1922.