Fergus

wiktionary

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From Irish or Scottish Gaelic Fearghas. The first element may be related to modern fìor(“true”) or fear(“man”) (cf. Fearchar). The second element has been understood to mean 'choice' (cf. Angus). Thus the name means either "most chosen one" or "chosen man". [1]

etymonline

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Fergus

masc. proper name, from Gaelic Fearghus or Old Irish Fergus "man-ability," first element cognate with Latin vir "man" (from PIE root *wi-ro- "man"); second from Old Irish gus "ability, excellence, strength, inclination," from Celtic root *gustu- "choice," from PIE root *geus- "to taste; to choose."