compunctious

noun

1. a sharp feeling of uneasiness brought on by a sense of guilt; remorse
2. a feeling of slight regret for something done

Origin: ME compunccion < OFr compunction < LL compunctio, a pricking (in LL(Ec), the pricking of conscience) < L compunctus, pp. of compungere, to prick, sting < com-, intens. + pungere, to prick: see point