unreasonable vs excessive

unreasonable and excessive both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unreasonable	No	Yes	No	No
excessive	No	Yes	No	No

As adjectives, unreasonable and excessive are synonyms defined as:

Other synonyms of unreasonable include inordinate, undue.

unreasonable (adjective)	excessive (adjective)
not reasonable; not showing good judgment	beyond normal limits
beyond normal limits	unrestrained, especially with regard to feelings