trojan (Adjective) — Of or relating to the ancient city of Troy or its inhabitants. ex. "Trojan cities"
trojan (Noun) — A program that appears desirable but actually contains something harmful. ex. "the contents of a trojan can be a virus or a worm" ex. "when he downloaded the free game it turned out to be a trojan horse"
trojan (Noun) — A native of ancient Troy.