A distinguishing trait is a unique feature or characteristic that sets something apart from other similar things. EARMARK, HALLMARK, and TRADEMARK are all terms used to describe a distinguishing trait. An EARMARK is a mark or sign that identifies the owner of an animal or item. A HALLMARK is a mark or symbol that indicates the quality or origin of a product. A TRADEMARK is a distinctive sign or symbol used to identify a product or service as belonging to a particular company.