舌したっ足たらず

1unclear speech ; garbled speech ; poor enunciation Translated by Jiyomi
2poorly expressed ; unclear (wording) ; imprecise (expression) ; inadequate (explanation)

noun (common) (futsuumeishi) · adjectival nouns or quasi-adjectives (keiyodoshi) · nouns which may take the genitive case particle 'no'

JMdict entry 2868650. Source and licence.