Feel modest about large plant (3)
I believe the answer is:
elm
'large plant' is the definition.
'elm' can be an answer for 'plant' (I have seen 'Perennial plant' mean 'elm' so perhaps 'plant' could also mean 'elm'). I am unsure of the 'large' bit.
'feel modest about' is the wordplay.
'about' says the answer is hidden in the clue (the clue goes around or about the answer).
'ELM' is hidden within 'feel modest'.
Can you help me to learn more?
(Other definitions for elm that I've seen before include "Kind of tree" , "What's seen in parks" , "Wood in pelmet" , "Deciduous tree with light serrated leaves" , "Perennial plant" .)