"tall and sturdy, robust," originally applied to women, 1650s, from present participle of strap (v.), apparently in the sense of "to beat with a strap." Compare similar senses of whopping, spanking, bouncing and other present-participle adjectives of violent action expressing something large in size.
1640s, "springing back, returning to the original position," from Latin resilientem "inclined to leap or spring back," present participle of resilire "to jump back" (see resilience). Of material things, "resuming original shape after compression, etc.," by 1670s. Figuratively, of persons "bouncing back" from difficulties, etc., from 1830. Related: Resiliently.
by c. 1200 as an emphatic form of Old English of (see of), employed in the adverbial use of that word. The prepositional meaning "away from" and the adjectival sense of "farther" were not firmly fixed in this variant until 17c., but once they were they left the original of with the transferred and weakened senses of the word. Meaning "not working" is from 1861.
Off the cuff "extemporaneously, without preparation" (1938) is from the notion of speaking from notes written in haste on one's shirt cuffs. In reference to clothing, off the rack (adj.) "not tailored, not made to individual requirements, ready-made" is by 1963, on the notion of buying it from the rack of a clothing store; off the record "not to be publicly disclosed" is from 1933; off the wall "crazy" is 1968, probably from the notion of a lunatic "bouncing off the walls" or else in reference to carom shots in squash, handball, etc.