Tongue-tied single, taciturn with ale drunk (12)
I believe the answer is:
Here is my best explanation:
'tongue-tied' is the definition.
('inarticulate' can be similar in meaning to 'tongue-tied')
'single taciturn with ale drunk' is the wordplay.
'single' becomes 'i' (one).
'with' means one lot of letters go next to another.
'drunk' is an anagram indicator.
'taciturn' after 'ale' is 'aletaciturn'.
'aletaciturn' is an anagram of 'narticulate'.
(Other definitions for inarticulate that I've seen before include "Incomprehensible", "Unintelligible", "Lacking fluency", "I taunt a relic (anag.)", "Unable to express oneself clearly", "Unable to speak clearly", "being tongue-tied", "hard to understand", "incoherent" and "Not able to speak coherently".)