Letters that make whacko
a, o, k, c, h, w are letters that make 'whacko'
whackos is a word created by adding a letter to 'whacko'
1 possible definitions for 'whacko'
Under this definition, whacko is a noun and has the following properties:
'whacko' can be a type of eccentric person, oddball, geek, flake, eccentric.