Weep thus alongside bishop (3)
I believe the answer is:
sob
'weep' is the definition.
(sobbing is a kind of weeping)
'thus alongside bishop' is the wordplay.
'thus' becomes 'so' (synonyms).
'alongside' is a charade indicator (letters next to each other).
'bishop' becomes 'B' (abbreviation used in chess).
'so'+'b'='SOB'
(Other definitions for sob that I've seen before include "Weep uncontrollably" , "Cry uncontrollably" , "Weeping gasp" , "Contemptible person in North America briefly" , "Insulting expression, initially" .)