Strangely endearing cocktail ingredient (9)
I believe the answer is:
grenadine
'cocktail ingredient' is the definition.
(grenadine is an ingredient in many cocktails)
'strangely endearing' is the wordplay.
'strangely' indicates an anagram.
'endearing' anagrammed gives 'GRENADINE'.
(Other definitions for grenadine that I've seen before include "material" , "Pomegranate juice syrup" , "Pomegranate cordial" , "West Indian" , "silk fabric" .)