Definitions

1. interjection

an expression of surprise, shock, or confusion

“She let out a loud ‘wha’ when she saw the surprise party.”

2. noun

the sound of a sudden exhalation, especially of surprise or shock

“The wha of the crowd echoed through the stadium.”

3. verb

to utter a sudden exhalation, especially of surprise or shock

“She wha’d in shock when she saw the news.”