Synonyms: incoherent, tongue-tied
Definition: unable to express yourself clearly or fluently
Usage: felt tongue-tied with embarrassment; incoherent with grief
Similar words: unarticulate, inarticulate
Definition: without or deprived of the use of speech or words
Usage: inarticulate beasts; remained stupidly inarticulate and saying something noncommittal; inarticulate with rage; an inarticulate cry