compunction

Concise Oxford English Dictionary © 2008 Oxford University Press:
compunction/kəmˈpʌŋkʃn/

▶noun a feeling of guilt or moral scruple that prevents or follows a bad action.

– derivatives
compunctious adjective,
compunctiously adverb.

– origin ME: from OFr. componction, from eccles. L. compunctio(n-), from L. compungere ‘prick sharply’.