deplorern.

/dɪˈplɔːrə/Etymology: formed as deplore v. + -er suffix1.
the mind > emotion > suffering > sorrow or grief > lamentation or expression of grief > [noun] > lamenter(s)
1687 R. Boyle (1703) xi. 167 All the other spectators of her sufferings, were deplorers of them too.
This entry has not yet been fully updated (first published 1895; most recently modified version published online September 2018).