pigtail vs plait

pigtail and plait both are nouns.

Word	Noun	Adjective	Verb	Adverb
pigtail	Yes	No	No	No
plait	Yes	No	Yes	No

As nouns, plait is a hypernym of pigtail; that is, plait is a word with a broader meaning than pigtail:

Other hypernyms of pigtail include braid, tress, twist.

pigtail (noun)	plait (noun)
a plait of braided hair	any of various types of fold formed by doubling fabric back upon itself and then pressing or stitching into shape
	a hairdo formed by braiding or twisting the hair

pigtail (verb)	plait (verb)
	weave into plaits
	make by braiding or interlacing