It may be a squash (5)
I believe the answer is:
fruit
This clue might be a double definition.
'it' is the first definition.
The definition suggests a singular noun which matches the answer.
'a squash' is the second definition.
The answer and definition can be both plants as well as being singular nouns.
Maybe there's a link between them I don't understand?
'may be' is the link.
Can you help me to learn more?
(Other definitions for fruit that I've seen before include "Reward of activity" , "Result - food" , "Result of work/activity" , "Apples, pears etc" , "Eg, bananas" .)