On Purpose
Deliberately, Intentionally
adverb
So this doesn't quite make sense in terms of the meaning of the kanji... but you'll be okay. This means on purpose. Perhaps when you do something that has the appearance of doing what you wanted to do you're doing it on purpose.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: "You did that to me on purpose? Whazapp with that?"
このお皿、ヒビが入ってるみたいに見えるけど、態とそういうデザインなの！
This plate looks like it has a crack in it, but it's designed that way on purpose!
今の価格って、態とつり上げられたものなんじゃないかと思ってるんです。
I suspect that the current prices are deliberately inflated.
彼女は、彼に態と気のないふりをした。
She pretended to be indifferent toward him on purpose.