Inarticulate means unable to get the words out clearly. The right thought arrives and the sentence will not.
It describes two rather different failures. One is temporary and emotional — inarticulate with rage, inarticulate with grief — where feeling has simply overwhelmed speech, and that use is sympathetic. The other is a lasting judgement about somebody who cannot express themselves well, and that one stings. The word also covers sounds rather than people: an inarticulate cry is one with no words in it. Its opposite, articulate, is one of the commonest compliments in English.
1adjectiveinarticulateUnable to express yourself clearly in speech.
“He was inarticulate with fury and could only point.”
2adjectivesoundOf a sound, having no clear words in it.
“She gave an inarticulate cry of surprise.”
Latin
inarticulatus
English, today
inarticulate
From Latin inarticulatus and from in + articulate. See -ate.
Etymology from Wiktionary, CC BY-SA