Whackass is a general term to describe someone you do not like:
Madelyn: Is that Tyler's ex?
Carrie: Yeah she is a whackass, in fact all they are all whackasses.
when someone is whack, just a harsher version of it. comes from root word whack which means dumb or a word to define someone who is obviously exaggerating. can mean wrong. usually meant in a playful sense.
A rip snorter of a saying invented by two true blue Aussies down in Melbourne way meaning "no worries." Why say no worries when you can up the ante, have a fair crack at the sauce and yell out no whackas? Sure it might sound stranger than the Titanic in the middle of the Arabian desert, but use it, and folks will be deadset fair dinkum as happy as Larry! We reckon the phrase should spread worldwide, Oxford, if ya reading this Shakespeare please chuck it on ya dictionary!
No whackas/no quackers, made up slang meaning "no worries."
"Thanks for sending those docos over mate"
"Yeah no whackas!"
OR
"Thanks for the meat pie mate"
"Yeah no quackers!"