aha
interj. B2 Upper Intermediate US //ˌɑˈhɑ// UK //ɑːhˈɑː// aha
interj. a sound you make when you suddenly understand something or find the answer to a problem. You use it to show you are surprised or happy about a new discovery.
interj. an exclamation used to express sudden realization, triumph, or discovery. Often used when a previously hidden truth or solution becomes apparent.
Aha! I finally found where I left my keys.
Aha! So you were the one who ate the last piece of cake after all.
The detective stared at the ledger for hours until, with a sudden 'Aha!', he realized the dates had been falsified to hide the missing funds.
Usage
Used as a standalone exclamation or to introduce a sentence; typically followed by a comma or an exclamation mark.