log·ger·head / ˈlôgərˌhed; ˈlägər-/ • n. 1. (also loggerhead turtle) a reddish-brown turtle (Caretta caretta, family Cheloniidae) with a very large head, occurring chiefly in warm seas. 2. (also loggerhead shrike) a widespread North American shrike (Lanius ludovicianus), having mainly gray plumage with a black eyestripe, wings, and tail. 3. archaic a foolish person.PHRASES: at loggerheads in violent dispute or disagreement: council was at loggerheads with the government.