Enter home quietly removing contents of unit (5)
I believe the answer is:
input
'enter' is the definition.
(I've seen this in another clue)
'home quietly removing contents of unit' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'quietly' becomes 'p' (p for piano and quiet).
'removing' becomes 'u' (I am not sure about this - if you are sure you should believe this answer much more).
'contents of' says to take the centre (letters inside the word).
'unit' becomes 'metre' (unit of distance).
The middle of 'metre' is 't'.
'in'+'p'+'u'+'t'='INPUT'
Can you help me to learn more?
(Other definitions for input that I've seen before include "Data contributed" , "store" , "Person's contribution (to activity); electrical signal" , "Comment, contribution" , "Contribution; enter (data)" .)