Is not half overwhelmed by upset we ought to overcome (8)
I believe the answer is:
outweigh
'overcome' is the definition.
(thesaurus)
'is not half overwhelmed by upset we ought' is the wordplay.
'not half' suggests halving the letters.
'overwhelmed by' is an insertion indicator (I've seen this in other clues).
'upset' indicates anagramming the letters.
'is' halved is 'i'.
'we'+'ought'='weought'
'weought' with letters rearranged gives 'outwegh'.
'i' inserted within 'outwegh' is 'OUTWEIGH'.
'to' is the link.
(Other definitions for outweigh that I've seen before include "Exceed in importance" , "dated fashion, we hear" , "Be heavier or more significant than" , "Preponderate" , "Have more influence" .)