Mass rejection of mouthpiece for computers perhaps? (4)
I believe the answer is:
pile
'mass' is the definition.
(synonyms)
'rejection of mouthpiece for computers perhaps?' is the wordplay.
'rejection of' says the letters should be written backwards.
'mouthpiece' becomes 'lip' (part of the mouth).
'for' says to put letters next to each other.
'computers perhaps?' becomes 'e' (I can't justify this - if you can you should give a lot more credence to this answer).
'lip' in reverse letter order is 'pil'.
'pil'+'e'='PILE'
Can you help me to learn more?
(Other definitions for pile that I've seen before include "Large number" , "Stake" , "Fortune" , "Post" , "lot of money" .)