May return small orange vegetables (4)
I believe the answer is:
yams
'orange vegetables' is the definition.
(I've seen this in another clue)
'may return small' is the wordplay.
'return' is a reversal indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'may' in reverse letter order is 'yam'.
'yam'+'s'='YAMS'
(Other definitions for yams that I've seen before include "Roots" , "vegetables" , "Sweet potatoes" , "Edible tubers from the tropics" .)