Like an egg -- veto a pie (5)
I believe the answer is:
ovate
'like an egg' is the definition.
(I've seen this in other clues)
'veto a pie' is the wordplay.
'pie' indicates an anagram.
'veto'+'a'='vetoa'
'vetoa' with letters rearranged gives 'OVATE'.
(Other definitions for ovate that I've seen before include "Shaped like an egg" , "applaud enthusiastically?" , "philosopher" , "Like Humpty Dumpty" , "Egg-shaped - eisteddfodic graduate" .)