The meaning of IMPOSING is impressive in size, bearing, dignity, or grandeur. How to use imposing in a sentence. Synonym Discussion of Imposing. / ɪmˈpoʊ.zɪŋ / Add to word list having an appearance that looks important or causes admiration: an imposing mansion Imposing is an adjective reserved for those things that are impressive in the sense that they are large or serious, as in the US Capitol Building or even, say, a professional wrestler. If you describe someone or something as imposing, you mean that they have an impressive appearance or manner. He was an imposing man. ...the imposing wrought-iron gates at the entrance to the estate. Definition of imposing adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.