wacky

As an adjective wacky

is of a person or their behaviour, zany.

As a noun wacky

is .

As an adverb wackily is

in a way or to an extent that is wacky.

As adjectives the difference between wacky and wackadoo

is that wacky is of a person or their behaviour, zany while wackadoo is crazy, wacky.

As nouns the difference between wacky and wackadoo

is that wacky is alternative form of lang=en while wackadoo is a crazy person, a wacko.