closely (adv.)

(klōs), late 14c., "strictly confined," also "secret," from Old French clos "confined; concealed, secret; taciturn" (12c.), from Latin clausus "close, reserved," past-participle adjective from claudere "stop up, fasten, shut" (see close (v.)); main sense shifting to "near" (late 15c.) by way of "closing the gap between two things." Related: Closely.

Meaning "narrowly confined, pent up" is late 14c. Meaning "near" in a figurative sense, of persons, from 1560s. Meaning "full of attention to detail" is from 1660s. Sense of "stingy, penurious" is from 1650s. Of contests, from 1855.

Close call "narrow escape" is from 1866, in a quotation in an anecdote from 1863, possibly a term from the American Civil War; close shave in the figurative sense is 1820, American English. Close range (n.) "a short distance" is from 1814. Close-minded is attested from 1818. Close-fisted "penurious, miserly" is from c. 1600, on the notion of "keeping the hands tightly shut."

common adverbial suffix, forming from adjectives adverbs signifying "in a manner denoted by" the adjective, Middle English, from Old English -lice, from Proto-Germanic *-liko- (cognates: Old Frisian -like, Old Saxon -liko, Dutch -lijk, Old High German -licho, German -lich, Old Norse -liga, Gothic -leiko); see -ly (1). Cognate with lich, and identical with like (adj.).

Weekley notes as "curious" that Germanic uses a word essentially meaning "body" for the adverbial formation, while Romanic uses one meaning "mind" (as in French constamment from Latin constanti mente). The modern English form emerged in late Middle English, probably from influence of Old Norse -liga.