offspring (n.)

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.

Middle English springen, from Old English springan "to leap, leap up, jump;" of a fountain, spring, etc., "burst forth;" also "fly up; spread, grow" (class III strong verb; past tense sprang, past participle sprungen). This is from Proto-Germanic *sprenganan (source also of Old Norse springa "burst," Old Frisian springa, Middle Dutch springhen, Dutch springen, Old Saxon and Old High German springan, German springen "jump"). This is usually said to be from PIE *sprengh-, a nasalized form of root *spergh- "to move, hasten, spring" (source also of Sanskrit sprhayati "desires eagerly," Greek sperkhesthai "to hurry"). However Boutkan is attracted to an alternative derivation from PIE root *sper- "to spread, to sow" (for which see sparse).

In Middle English, it took on the role of causal sprenge, from Old English sprengan (as still in to spring a trap, etc.). The meaning "to cause to work or open," by or as by a releasing of the spring mechanism, is from 1828.

The transitive meaning "announce suddenly, bring out hastily and unexpectedly" (usually with on) is from 1876. The meaning "to release" (from imprisonment) is from 1900. The slang meaning "to pay" (for a treat, etc.) is recorded from 1906.