Mournful English, and Gaelic outpouring (7)
I believe the answer is:
elegiac
'mournful' is the definition.
(synonym)
'english and gaelic outpouring' is the wordplay.
I cannot quite see how this works, but
'english' could be 'e' (abbreviation) and 'e' is present in the answer.
an anagram of 'gaelic' is 'legiac' which is within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for elegiac that I've seen before include "Mournful, lamenting" , "Wistful, mournful" , "Poetic, mournful" , "of valedictory works" , "Lie in cage being poetically mournful" .)