Fergus is an Irish and Scottish Gaelic name meaning "man of vigor" and it sounds like exactly that: two syllables, the hard F opener, the G in the middle giving it heft, the -us ending that parks itself firmly. It's a name that takes up space without apologizing, and certain dogs need exactly that kind of name.
Celtic Heritage, Sturdy Personality
Fergus comes from Old Irish Fergus, derived from fear (man) and gus (vigor or strength). It's a name with genuine pedigree in Irish and Scottish history — the legendary warrior Fergus mac Roich appears in the Ulster Cycle of Irish mythology. On a dog, that heritage reads as sturdy, good-humored, and reliably capable. The human name Fergus is far more common in the UK and Ireland than in the US, which gives the pet version a transatlantic character.
Breed Fit
Fergus is almost universally applied to male dogs, and it gravitates toward medium-to-large breeds with Scottish or Irish heritage: Irish Wolfhounds, Scottish Terriers, and Border Collies. The name on a Scottish Terrier specifically is a coherent cultural package that dog people notice and appreciate.
The Case for Unfashionable Names
Fergus doesn't appear in any trending pet name list. That's a point in its favor. Names that aren't fashionable don't become overexposed, and Fergus has enough personality to hold attention on its own merits. Angus and Hamish are natural companions in the same Celtic register.