Tory locum beginning to transmit disdain (8)
I believe the answer is:
contempt
'disdain' is the definition.
(I know that disdain can be written as contempt)
'tory locum beginning to transmit' is the wordplay.
'tory' becomes 'con' (abbreviation for Conservative).
'locum' becomes 'temp' (temporary worker).
'beginning to' suggests taking the first letters.
The initial letter of 'transmit' is 't'.
'con'+'temp'+'t'='CONTEMPT'
(Other definitions for contempt that I've seen before include "Undisguised disrespect" , "Open disrespect, to a court, say" , "Disdain or disrespect, perhaps or court" , "Feeling of disdain, perhaps of court" , "Scorn; disgrace" .)