Bellows, losing head in rows (4)
I believe the answer is:
oars
'rows' is the definition.
(I've seen this before)
'bellows losing head' is the wordplay.
'bellows' becomes 'roars' ('roar' can be a synonym of 'bellow').
'losing head' means to remove the first letter.
'roars' with its initial letter removed is 'OARS'.
'in' is the link.
(Other definitions for oars that I've seen before include "Sweeps" , "Manually operated boat propellers" , "Paddles" , "Manual boat propellers" , "Propelling implements" .)