late 14c., diffinicioun, definicion, "decision, setting of boundaries, determination and stating of the limits and distinctive nature of a thing," also "limitations," also "a statement of the meaning of a word or phrase," from Old French definicion, from Latin definitionem (nominative definitio) "a bounding, a boundary; a limiting, prescribing; a definition, explanation," the last sense most often in Cicero, noun of action from past-participle stem of definire "to limit, determine, explain," from de "completely" (see de-) + finire "to bound, limit," from finis "boundary, end" (see finish (v.)). In logic, meaning "act of stating what something means" is from 1640s. Meaning "degree of distinctness of the details in a picture" is from 1889.
"of the nature of an aphorism," 1753, from Latinized form of Greek aphoristikos, from aphorismos "definition, pithy sentence" (see aphorism). Related: Aphoristically (1650s). Aphorismic "having the form of an aphorism" is from 1794.
"pertaining to or dealing with the context," 1822, from context on model of textual, etc. In philosophy, contextual definition is recorded from 1873, contextualization from 1930, contextualizefrom 1934. Related: Contextualized; contextualizing; contextually.
"act of cutting down and clearing away the forests of a region or tract," 1870, noun of action from deforest (q.v.). Earlier was deforesting (1530s) which was a legal term for the change in definition of a parcel of land from "forest" to something else.
"chemical released by an animal that causes a specific response when detected by another animal of the same species," but the exact definition is much debated; 1959, coined (by Karlson & Lüscher) from Greek pherein "to carry" (from PIE root *bher- (1) "to carry," also "to bear children") + ending as in hormone.
"things important for a ship but in the way at certain times" (Klein's definition), 1835, from hamper (n.) "a fetter, shackles," from French hamper "to impede." Hence top hamper, originally "upper masts, spars, rigging, etc. of a sailing ship."