nymphomaniac vs nymphomaniacal

nymphomaniac is a noun but nymphomaniacal is not a noun.

Word	Noun	Adjective	Verb	Adverb
nymphomaniac	Yes	Yes	No	No
nymphomaniacal	No	Yes	No	No

As adjectives, nymphomaniac and nymphomaniacal are synonyms defined as:

nymphomaniac and nymphomaniacal: (used of women) affected with excessive sexual desire

nymphomaniac (noun)	nymphomaniacal (noun)
a woman with abnormal sexual desires

nymphomaniac (adjective)	nymphomaniacal (adjective)
(used of women) affected with excessive sexual desire	(used of women) affected with excessive sexual desire