haphazardly vs willy-nilly

haphazardly and willy-nilly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
haphazardly	No	No	No	Yes
willy-nilly	No	No	No	Yes

As adverbs, haphazardly and willy-nilly are synonyms defined as:

Other synonyms of haphazardly include arbitrarily, at random, every which way, indiscriminately, randomly.

haphazardly (adverb)	willy-nilly (adverb)
in a random manner	in a random manner
without care; in a slapdash manner	without having a choice