Initially doubt urge to discard (5)
I believe the answer is:
ditch
'discard' is the definition.
(thesaurus)
'initially doubt urge' is the wordplay.
'initially' indicates taking the first letters.
'urge' becomes 'itch' (I've seen this before).
The first letter of 'doubt' is 'd'.
'd'+'itch'='DITCH'
'to' acts as a link.
(Other definitions for ditch that I've seen before include "Drainage channel" , "Dump (informal)" , "Drop" , "drainage feature" , "Boundary trench" .)