obvusly
Obvusly is when you’re so sure something is dumb that you don’t even need to think, you just say it like it's a swear word and laugh at them.
Your friend says they’re going to win the race, and you say, 'Obvusly.'
Your little brother says he’s going to eat your lunch, and you say, 'Obvusly.'
Your dog chases its tail, and you say, 'Obvusly.'