haul vs piggyback

haul and piggyback both are nouns.

Word	Noun	Adjective	Verb	Adverb
haul	Yes	No	Yes	No
piggyback	Yes	No	Yes	Yes

As verbs, piggyback is a hyponym of haul; that is, piggyback is a word with a more specific, narrower meaning than haul:

haul (noun)	piggyback (noun)
the act of drawing or hauling something	the act of carrying something piggyback
the quantity that was caught

haul (verb)	piggyback (verb)
transport in a vehicle	bring into alignment with
draw slowly or heavily	support on the back and shoulders
	haul by railroad car
	haul truck trailers loaded with commodities on railroad cars
	ride on someone's shoulders or back

haul (adverb)	piggyback (adverb)
	on the back or shoulder or astraddle on the hip
	on a railroad flatcar