Gerald

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.

Proto-Indo-European root meaning "to be strong."

It forms all or part of: ambivalence; Arnold; avail; bivalent; convalesce; countervail; Donald; equivalent; evaluation; Gerald; Harold; invalid (adj.1) "not strong, infirm;" invalid (adj.2) "of no legal force;" Isold; multivalent; polyvalent; prevalent; prevail; Reynold; Ronald; valediction; valence; Valerie; valetudinarian; valiance; valiant; valid; valor; value; Vladimir; Walter; wield.

It is the hypothetical source of/evidence for its existence is provided by: Latin valere "be strong, be well, be worth;" Old Church Slavonic vlasti "to rule over;" Lithuanian valdyti "to have power;" Celtic *walos- "ruler," Old Irish flaith "dominion," Welsh gallu "to be able;" Old English wealdan "to rule," Old High German -walt, -wald "power" (in personal names), Old Norse valdr "ruler."