The word seems to be a hapax without any clear etymon. One possible interpretation is to read the three minims of ‘m’ as ‘ui’, and the word as puinance. In that case *poignance would be an otherwise unattested nominal derivative of poindre¹ which has the sense ‘(fig.) to sting, prick, cause pain or anguish’. Alternatively, puinance may be a deviant spelling of penance.