Full Definition of DIDACTIC. 1. a: designed or intended to teach. 2. : making moral observations. — di·dac·ti·cal \-ti-kəl\ adjective. — di·dac·ti·cal·ly \-ti-k(ə-)lē\ adverb. — di·dac·ti·cism \-tə-ˌsi-zəm\ noun. See didactic defined for English-language learners. See didactic defined for kids.