ungrammaticalPronunciation: /ʌngrəˈmatɪk(ə)l/Translate ungrammatical | into French | into German | into Italian Definition of ungrammatical adjective not conforming to grammatical rules:ungrammatical sentencesDerivatives ungrammaticalityPronunciation: /-ˈkalɪti/ noun (plural ungrammaticalities) ungrammatically adverb ungrammaticalness noun ungrammatical in other Oxford dictionaries Definition of ungrammatical in the US English dictionary