What does "betcha" mean?

Pronunciation spelling of bet you.

What is a synonym for "betcha"?

Common synonyms include: absolutely, bet, certainly, okay, risk, stake.

/ˈbɛt͡ʃə/ contraction, name, slang

contraction, name, slang ·Moderate ·College level

Contraction

1
Pronunciation spelling of bet you. alt-of, contraction, informal, pronunciation-spelling
"I betcha any money that that's the case."
2
Can be sure of it. contraction, informal, pronunciation-spelling
"You betcha! (meaning You can bet your bottom dollar!)"

Proper Noun

"Do I want to take that shiny new car off your hands? You betcha!"

From bet + -cha. Second sense possibly from bet your rather than bet you.