1620s, from in- (1) "not" + expressible (see express (v.)). Inexpressibles "trousers" is from 1790. Related: Inexpressibly.
I have retain'd the word BREECHES, as they are known by no other name amongst country folk.--The change from vulgarity to refinement, in cities and towns, has introduced other appellations; there they are generally called SMALL CLOTHES, but some ladies of high rank and extreme delicacy call them INEXPRESSIBLES. [footnote in "Poems Miscellaneous and Humorous," by Edward Nairne, Canterbury, 1791]
Inexpressibles is the earliest recorded and thus seems to have begotten the trend: Unmentionables (1806); indispensibles (1820); ineffables (1823); unutterables (1826); innominables (1827); and inexplicables (1829) followed.
"to put into a phrase, express by a particular phrase," 1560s; see phrase (n.). Related: Phrased; phrasing.
"portray or express emotion," especially theatrically, 1909, American English, back-formation from emotion. Related: Emoted; emoting.
1620s, "intended to express or convey a compliment," from compliment (n.) + -ary. In later use loosely meaning "free of charge."
1530s, "ask (someone) to (do something), express desire for something to be done;" 1560s, "express a wish or desire, ask to be allowed to do something," from request (n.) or from French requester, "ask again, request, reclaim," from requeste. The older verb was Middle English requeren (14c.), from Old French requerre and directly from Latin requiare. Related: Requested; requesting.