Send male in carriage (8)
I believe the answer is:
transmit
'send' is the definition.
('transmit' can be a synonym of 'send')
'male in carriage' is the wordplay.
'male' becomes 'm' (common abbreviation).
'in' indicates putting letters inside.
'carriage' becomes 'transit' (I've seen this before).
'm' inserted within 'transit' is 'TRANSMIT'.
(Other definitions for transmit that I've seen before include "Send - communicate" , "Pass on (message)" , "put out" , "Pass or hand on" , "F. name; Hamlet (anag.)" .)