Pant
Middle English: related to Old French pantaisier ‘be agitated, gasp’, based on Greek phantasioun ‘cause to imagine’, from phantasia (see fantasy).
wiktionary
From Middle English panten, whence also English dialectal pank.
Possibly from Old French pantoyer, a byform or of Old French pantoisier(“to be breathless”) (compare modern French panteler(“to gasp for breath”)), of uncertain origin. Possibly from Vulgar Latin *pantasiō(“struggling for breath when having a nightmare”), from Ancient Greek φαντασιόω(phantasióō, “I am subject to hallucinations”), from φαντασία(phantasía, “appearance, image, fantasy”).
From pants
Unknown
etymonline
pant (v.)
mid-14c., panten, "breathe hard or rapidly," perhaps a shortening of Old French pantaisier "gasp, puff, pant, be out of breath, be in distress" (12c.), which is probably from Vulgar Latin *pantasiare "be oppressed with a nightmare, struggle for breathing during a nightmare," literally "to have visions," from Greek phantasioun "have or form images, subject to hallucinations," from phantasia "appearance, image, fantasy" (from PIE root *bha- (1) "to shine"). Related: Panted; panting.
pant (n.)
"a gasping breath, a quick, short effort of breathing," c. 1500, from pant (v.).
