The answer is which, but you mean homophone, not homonym.
The homonym of "drenched" is "drentched."
The homonym for "mourning" is "morning".
A homonym for "grays" is "greys."
The homonym for 'census' is 'sense'.
Was is a linking verb. It does not have a homonym.
The homonym for 'suite' is 'sweet'.
The homonym for chord is cord.
The homonym for "vale" is "veil."
The homonym of sauce is "source".
The homonym for 'build' is 'billed'.
The homonym is sell