intransitive verb, ichidan verb
If you tear (てる) up a fruit, its life is going to end. In other words, the poor thing is going to die. Fruit can't go on when they've been beaten up so much.
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:
The fruit's life is about to end and you laugh, "Hahahaha (は)!" And then you start tearing at it more! What's wrong with you? Weirdo...
I thought, I must not die here.
I haven't slept for three days and I'm exhausted.
The meeting continued without any sign of ending and the employees were getting fed up.