The phrase "prick of conscience" refers to a feeling of guilt or remorse that is experienced when an individual goes against their moral beliefs. There are various synonyms for this term, such as twinge of conscience, pang of guilt, sting of remorse, pinch of regret, and tug of compunction. Each of these synonyms emphasizes the sudden and sharp nature of the feeling, which is often described as a physical sensation. Regardless of the term used, the experience of a prick of conscience is a reminder of one's ethical principles, and an opportunity to reflect on their actions and make amends where necessary.