Groups of pirates? (7)
I believe the answer is:
parties
'groups' is the definition.
The answer is an example.
'of pirates?' is the wordplay.
'of' indicates an anagram (the answer comes from or 'of' the letters).
'pirates' anagrammed gives 'PARTIES'.
(Other definitions for parties that I've seen before include "Celebrates" , "Social gatherings" , "Fun affairs for political groups" , "They may be thrown" , "celebratory occasions" .)