Forgo a farewell gesture we hear (5)
I believe the answer is:
waive
'forgo a farewell' is the definition.
'waive' can be an answer for 'forgo' (synonyms). I'm not certain of the 'a farewell' bit.
'gesture we hear' is the wordplay.
'gesture' becomes 'wave' (waving is a kind of gesturing).
'we hear' indicates a 'sounds like' (homophone) clue.
'wave' is a homophone of 'WAIVE'.
Can you help me to learn more?
(Other definitions for waive that I've seen before include "pass up" , "Refrain from insisting on right or claim" , "Not insist on (claim)" , "Refrain from insisting on right or privilege" , "Forgo right or claim" .)