succinctly adv.

early 15c., "having one's belt fastened tightly," from Latin succinctus "prepared, ready; contracted, short," past participle of succingere "tuck up (clothes for action), gird from below," from assimilated form of sub "up from under" (see sub-) + cingere "to gird" (see cinch (n.)). Sense of "brief, concise" first recorded 1530s. Related: Succinctness.

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.