Giants possibly sore about midnight? (5)
I believe the answer is:
ogres
'giants' is the definition.
(ogre is a kind of giant)
'possibly sore about midnight?' is the wordplay.
'possibly' indicates an anagram.
'about' indicates putting letters inside.
'midnight?' becomes 'g' (the middle letter in 'night').
'sore' is an anagram of 'ores'.
'ores' enclosing 'g' is 'OGRES'.
(Other definitions for ogres that I've seen before include "Monsters can be goers" , "Giants in fairytales" , "intimidating people" , "Gorse (anag.)" , "Formidable people" .)