masc. proper name, French Gervais, from Old High German Gervas, literally "serving with one's spear," from ger "spear" (see gar) + Celtic base *vas- "servant," from Old Celtic *wasso- "young man, squire" (see vassal).
pike-like fish, 1765, American English, shortening of garfish (mid-15c.), from fish (n.) + Middle English gare, gore "a spear," from Old English gar "spear," from Proto-Germanic *gaisa- "spear" (source also of Old Norse geirr "spear; point of an anvil," Old Saxon, Old High German ger, German Ger "spear"), from PIE *ghaiso- "a stick, spear" (see goad (n.)). The fish so called for its long sharp snout. Compare Edgar, garlic.
early 14c. (c. 1200 as a surname) "tenant who pledges fealty to a lord," from Old French vassal "subject, subordinate, servant" (12c.), from Medieval Latin vassallus "manservant, domestic, retainer," extended from vassus "servant," from Old Celtic *wasso- "young man, squire" (source also of Welsh gwas "youth, servant," Breton goaz "servant, vassal, man," Irish foss "servant"), literally "one who stands under," from PIE root *upo "under." The adjective is recorded from 1580s.
<a href="https://www.etymonline.com/word/gervais">Etymology of gervais by etymonline</a>
Harper, D. (n.d.). Etymology of gervais. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/gervais