Curse from Cornish listener? (5)
I believe the answer is:
swear
'curse' is the definition.
(synonyms)
'cornish listener?' is the wordplay.
'cornish' becomes 'SW' (Cornwall is in the South West of England).
'listener?' becomes 'ear' (body part which hears or listens).
'sw'+'ear'='SWEAR'
'from' is the link.
(Other definitions for swear that I've seen before include "Solemnly promise" , "Use indecent or blasphemous language" , "Affirm" , "Express annoyance" , "Avow" .)