A creative and light-hearted way of answering in the affirmative. Not entirely unassociated with puppy-like enthusiasm.
"Have you checked your inbox lately Elizabeth?" "Yupsies!" she replied.
by PinkyBinkyBear March 03, 2011
1 more definition
Modern way of saying yea,yea,yep,yup.
Guy: Wanna go for a ride?
by MS! November 10, 2009