wailful vs wailing

wailful is not a noun while wailing is a noun.

Word	Noun	Adjective	Verb	Adverb
wailful	No	Yes	No	No
wailing	Yes	Yes	No	No

As adjectives, wailful and wailing are synonyms defined as:

wailful and wailing: vocally expressing grief or sorrow or resembling such expression

Other synonyms of wailful include lamenting.

wailful (noun)	wailing (noun)
	loud cries made while weeping

wailful (adjective)	wailing (adjective)
vocally expressing grief or sorrow or resembling such expression	vocally expressing grief or sorrow or resembling such expression