"like an oaf, stupid, dull," 1610s, from oaf + -ish. Related: Oafishly; oafishness.

"tree or shrub of the genus Quercus," Middle English oke, from Old English ac "oak tree" and in part from cognate Old Norse eik, both from Proto-Germanic *aiks (source also of Old Saxon and Old Frisian ek, Middle Dutch eike, Dutch eik, Old High German eih, German Eiche, Swedish ek, Danish eg), a word of uncertain origin with no certain cognates outside Germanic.

The usual Indo-European base for "oak" (*deru-) has become Modern English tree (n.). In Greek and Celtic, meanwhile, words for "oak" are from the Indo-European root for "tree." All this probably reflects the importance of the oak, the monarch of the forest, to ancient Indo-Europeans. Likewise, as there were no oaks in Iceland, the Old Norse word eik came to be used by the viking settlers there for "tree" in general.

In English the word is used in Biblical translations to render Hebrew elah (probably usually "terebinth tree") and four other words. The form in Middle English was very uncertain (oc, oek, hokke, ake, eoke, aike, hock, etc.). Oak-gall "excrescence produced by an oak tree in reaction to insects," used in making ink, is by 1712.

"made of, or consisting of, the wood of the oak," late 14c. (12c. in surnames and place-names), oken, from oak + -en (2). Similar formation in Old Frisian eken, Dutch eiken, Old High German eichen, German eichen, Old Norse eikinn.

"coarse, loose fiber obtained from taking apart old hemp ropes," used for caulking the seams of wooden ships, etc., early 15c., okam, okum, from Old English acumba "tow, oakum, flax fibers separated by combing," literally "what is combed out," from Proto-Germanic *us-kambon (source of Old High German achambi). The first element is cognate with Old English a- "away, out, off;" the second element is from stem of cemban "to comb," from camb "a comb;" from PIE root *gembh- "tooth, nail."

"long wooden lever for propelling a boat," Middle English or, from Old English ar, from Proto-Germanic *airo (source also of Old Norse ar, Danish aare, Swedish åra), a word of unknown origin. Apparently unrelated to the IE root that is the source of Latin remus "oar," Greek eretēs "rower," eretmos "oar," English row (v.) and rudder. As "oar-like appendage of an animal," 1580s.

A long oar, used occasionally to assist a vessel in a calm, is a sweep, and is operated by two or more men. Small oars are sculls; one rower wielding a pair, sitting midlength of the thwart. ["Knight's American Mechanical Dictionary," 1884]

"hole or indentation in the gunwale of a boat where an oar rests," mid-14c., or-lok, from oar + lock (n.1).

"one who rows with an oar," mid-15c., from genitive of oar (n.) + man (n.).

"fertile spot in a desert, where there is a spring or well and more or less vegetation," originally in reference to the Libyan desert, 1610s, from French oasis (18c.) and directly from Late Latin oasis, from Greek oasis, probably from Hamitic (compare Coptic wahe, ouahe "oasis," properly "dwelling place," from ouih "dwell"). The same Egyptian source produced Arabic wahah. Figurative sense of "any fertile place in the midst of a waste" is by 1800.

type of cereal plant, Middle English ote, from Old English ate (plural atan) "grain of the oat plant, wild oats," a word of uncertain origin, possibly from Old Norse eitill "nodule," denoting a single grain, itself of unknown origin. The English word has cognates in Frisian and some Dutch dialects. Famously defined by Johnson as, "A grain, which in England is generally given to horses, but in Scotland supports the people." Related: Oats.

The usual Germanic name is derived from Proto-Germanic *khabran (source also of Old Norse hafri, Dutch haver, source of haversack). Figurative wild oats "youthful excesses" (the notion is "crop that one will regret sowing") is attested by 1560s, in reference to the folly of sowing these instead of good grain. Hence, feel (one's) oats "be lively," 1831, originally American English.

That wilfull and vnruly age, which lacketh rypenes and discretion, and (as wee saye) hath not sowed all theyr wyeld Oates. [Thomas Newton, "Lemnie's Touchstone of complexions," 1576]

Fred: I still want to sow some wild oats!

Lamont: At your age, you don't have no wild oats, you got shredded wheat.

["Sanford and Son"]

"consisting of oats or oatmeal," late 14c., oten, from oat + -en (2). Also "made of stem of the straw of oats," as shepherd's pipes were in poetry.