Entry 1 sense Webster, 1913 Signpost /sīn'-pōstˌ/ · Sign·post · IPA /ˈsaɪnˌpoʊst/ 01 n. A post on which a sign hangs, or on which papers are placed to give public notice of anything. 1. A post on which a sign hangs, or on which papers are placed to give public notice of anything.