Clement arranged a binge at the Nag's Head (6)
I believe the answer is:
'clement' is the definition.
'arranged a binge at the nag's head' is the wordplay.
'arranged' is an anagram indicator.
'at' is a charade indicator (letters next to each other).
'head' says to take the initial letters.
The first letter of 'nags' is 'n'.
'binge' anagrammed gives 'benig'.
(Other definitions for benign that I've seen before include "Salubrious" , "Mild and gentle, not malignant" , "Medically curable" , "Genial; not harmful" , "Liberal" .)