Mangle words at first with one calling (7)
I believe the answer is:
wringer
'mangle' is the definition.
(I've seen this before)
'words at first with one calling' is the wordplay.
'at first' says to take the initial letters.
'with' is a charade indicator (letters next to each other).
'one calling' becomes 'ringer' (I've seen this before).
The initial letter of 'words' is 'w'.
'w'+'ringer'='WRINGER'
(Other definitions for wringer that I've seen before include "Old-fashioned clothes dryer" , "Old clothes dryer" , "Kitchen appliance" , "trouble when put through this?" , "A mangle" .)