off-the-wall vs outlandish

off-the-wall and outlandish both are adjectives.

Word	Noun	Adjective	Verb	Adverb
off-the-wall	No	Yes	No	No
outlandish	No	Yes	No	No

As adjectives, off-the-wall and outlandish are synonyms defined as:

off-the-wall and outlandish: conspicuously or grossly unconventional or unusual

Other synonyms of off-the-wall include bizarre, eccentric, flakey, flaky, freakish, freaky, gonzo, outre.

off-the-wall (adjective)	outlandish (adjective)
conspicuously or grossly unconventional or unusual	conspicuously or grossly unconventional or unusual