PEUK-, PEUG-, L pungere, punt-, to prick, whence PUNCTURE, the POINTed object that makes one, PUNCTUATE (add "points"--periods, etc.--to), the PUNGENT odor that pricks our noses, and the POIGNANT experience that "pricks" our hearts. A possible relative is L pugnare, fight (? "prick") with the fist, whence PUGILIST and PUGNACIOUS, probably < the same source ia a Gc verb = to penetrate ("prick") or strike ("bang"), whence FUCK.

Claiborne, Robert, the Roots of English, Times Books, 1989, page 195.