Intimate insect devours distressed diner (8)
I believe the answer is:
friendly
'intimate' is the definition.
(thesaurus)
'insect devours distressed diner' is the wordplay.
'insect' becomes 'fly' (fly is a kind of insect).
'devours' means one lot of letters goes inside another (I've seen this in other clues).
'distressed' indicates an anagram.
'diner' anagrammed gives 'riend'.
'fly' going around 'riend' is 'FRIENDLY'.
(Other definitions for friendly that I've seen before include "on the same side" , "Well-disposed" , "match?" , "prepared to talk to fellow passengers?" , "Amiable" .)