Synonyms for Outlandish (same or very similar meaning)
WordNet sense 1 (conspicuously or grossly unconventional or unusual):
bizarre, eccentric, flaky, freakish, freaky, off-the-wall, outre, flakey, gonzo
WordNet sense 2 (not conventional or conformist):
unconventional
From the ODE community, based on WordNet
add/edit