"in an amusing manner, comically," 1814, from funny + -ly (2).
Entries linking to funnily
funny adj.
"humorous," 1756, from fun (n.) + -y (2). Meaning "strange, odd, causing perplexity" is by 1806, said to be originally U.S. Southern (marked as colloquial in Century Dictionary). The two senses of the word led to the retort question "funny ha-ha or funny peculiar," which is attested by 1916. Related: Funnier; funniest. Funny farm "mental hospital" is slang from 1962. Funny bone "elbow end of the humerus" (where the ulnar nerve passes relatively unprotected) is from 1826, so called for the tingling sensation when struck. Funny-man was originally (1854) a circus or stage clown.
-ly 2
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.