Unremarkable cheese matures, drunk with port when half-cut (9)
I believe the answer is:
mousetrap
'unremarkable cheese' is the definition.
'mousetrap' can be an answer for 'cheese' (I've seen this before). I am unsure of the 'unremarkable' bit.
'matures drunk with port when half-cut' is the wordplay.
'drunk with' indicates anagramming the letters.
'when half-cut' means to take half the letters.
'port' with half the letters taken is 'po'.
'matures' with its letters anagrammed with 'po' makes 'MOUSETRAP'.
Can you help me to learn more?
(Other definitions for mousetrap that I've seen before include "Cheese-baited snare" , "Snare for vermin" , "Boring hard cheese (informal)" , "Cheap cheese" , "pest control device" .)