Bawl half-heartedly downstairs (5)
I believe the answer is:
below
'downstairs' is the definition.
('below' can be a synonym of 'downstairs')
'bawl half-heartedly' is the wordplay.
'bawl' becomes 'bellow' ('bellow' can be a synonym of 'bawl').
'half' indicates taking half.
'heartedly' becomes 'ow' (I've seen this in other clues).
'bellow' with half the letters taken is 'bel'.
'bel'+'ow'='BELOW'
(Other definitions for below that I've seen before include "Feel miserable" , "Lower than" , "Inferior" , "Beneath" , "Subordinate to" .)