Meaning

adverb (of quantities) imprecise but fairly close to correct

adverb with roughness or violence (`rough' is an informal variant for `roughly')

adverb with rough motion as over a rough surface

originEtymology tree English rough Proto-Indo-European *leyg-der. Proto-Germanic *līkąder. Proto-Germanic *-līkaz Proto-Germanic *-ê Proto-Germanic *-līkê Proto-West Germanic *-līkē Old English -līċe Middle English -ly English -ly English roughly From rough + -ly.

Etymology from Wiktionary, CC BY-SA 3.0