late 14c., "low, of little height," from Old French bas "low, lowly, mean," from Late Latin bassus "thick, stumpy, low" (used only as a cognomen in classical Latin, humilis being there the usual word for "low in stature or position"), possibly from Oscan, or Celtic, or related to Greek basson, comparative of bathys "deep."
Meaning "low on the social scale" is from late 15c.; that of "low in the moral scale" is first attested 1530s in English. Meaning "benefiting an inferior person or thing, unworthy" is from 1590s. Base metals (c. 1600) were worthless in contrast to noble or precious metals. Related: Basely.
<a href="https://www.etymonline.com/word/basset">Etymology of basset by etymonline</a>
Harper, D. (n.d.). Etymology of basset. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/basset