What is the crossword answer for the clue: Exclamation of discovery

AHA - a 3 letter word may be the answer you are looking for!

OHO - a 3 letter word may be the answer you are looking for!

EUREKA - a 6 letter word may be the answer you are looking for!

ITSYOU - a 6 letter word may be the answer you are looking for!

HAH - a 3 letter word may be the answer you are looking for!

Exclamation of discovery

3 Character Answers:

AHA

HAH

OHO

6 Character Answers:

EUREKA

ITSYOU