before vowels chrys-, word-forming element meaning "gold, gold-colored," also sometimes "wealth," from Latinized form of Greek khrysos "gold," which is usually said to be a Punic (Semitic) loan-word (compare Hebrew and Phoenician harutz "gold").

word-forming element meaning "around, round about, all around, on all sides," from Latin adverb and preposition circum "around, round about," literally "in a circle," probably accusative form of circus "ring" (see circus). The Latin word was commonly used in word-formation. In French, the element became circon-; Kitchin points out that con for cum is common even in classical Latin. For sense development, compare German rings "around."

word-forming element meaning, in meteorology, "involving cirrus clouds," and, in biology, "involving a tendril or tendrils," from combining form of Latin cirrus "lock of hair, tendril" (see cirrus).

word-forming element meaning "on the near side of, on this side," from Latin preposition cis "on this side" (in reference to place or time), related to citra (adv.) "on this side," from PIE *ki-s, suffixed form of root *ko-, the stem of demonstrative pronoun meaning "this." Opposed to trans- or ultra-. Originally only of place, sometimes 19c. of time; 21c. of life situations (such as cis-gender, which is attested by 2011).

initial consonant combination used in Old English (the Clark Hall dictionary has 82 entries under cn-), but not now admitted in speech, the n- only being sounded. In Middle English spelling all were lost or turned to kn-. It also is retained in the spelling of some Latinized words from Greek, where initial kn- was common.

in Latin, the form of com- "together, with" in compounds with stems beginning in vowels, h-, and gn-; see com-. Taken in English from 17c. as a living prefix meaning "together, mutually, in common," and used promiscuously with native words (co-worker) and Latin-derived words not beginning with vowels (codependent), including some already having it (co-conspirator).

before vowels coel-, word-forming element in scientific compounds meaning "hollow," from Latinized form of Greek koilos "hollow," from PIE root *keue- "to swell," also "vault, hole."