late 14c., sensibli, "in a manner perceived to the senses," from sensible + -ly (2). From 1670s as "in an appreciable degree;" the meaning "with good sense" is attested from 1755.
Entries linking to sensibly
sensible adj.
late 14c., "capable of sensation or feeling;" also "capable of being sensed or felt, perceptible to the senses," hence "perceptible to the mind, easily understood; logical, reasonable," from Old French sensible and directly from Late Latin sensibilis "having feeling: perceptible by the senses," from sensus, past participle of sentire "to perceive, feel" (see sense (n.)).
Of persons, from c. 1400 as "capable of mental perception, having good sense, clever, discerning;" by early 15c. as "aware, cognizant (of something)." Of actions, discourse, etc., "marked by or proceeding from (good) sense," 1650s. In reference to clothes, shoes, etc., "practical rather than fashionable," it is attested from 1855.
Other Middle English senses included "susceptible to injury or pain" (early 15c., common through 18c., now gone with sensitive); "worldly, temporal, outward" (c. 1400); "carnal, unspiritual" (early 15c., now gone with sensual). Related: Sensibleness.
-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.