wackadoo
noun
[ ˈwakəduː ]
• an eccentric or fanatical person.
• "he seems like a good guy even if he is a wackadoo"
wackadoo
adjective
• eccentric or fanatical.
• "out of the blue, he would do something completely wackadoo"
Origin:
1950s: probably from wack2 or wacky.
