Entry 1 sense Webster, 1913 Carlock /kär'-läkˌ/ · Car·lock · IPA /ˈkɑɹlɑk/ 01 n. A sort of Russian isinglass, made from the air bladder of the sturgeon, and used in clarifying wine. 1. A sort of Russian isinglass, made from the air bladder of the sturgeon, and used in clarifying wine.