To Happen, To Take Place
Intransitive verb and Godan verb
おこる
まさかこんなことが起こるなんて、思ってもみなかったよ。
I never expected something like this would happen.
今起こったことについて、落ち着いてよく考えてみてください。
Please calm down and think carefully about what's taken place.
「ねぇ、僕にキスしたい？」「ありえない。100万年経ってもあんたとキスなんて絶対にしたくないから。天地がひっくり返っても、起こりっこないよ。」
"Hey, do you want to kiss me?" "Absolutely no way would I ever want to kiss you in a million years. That would never happen even if heaven and earth were turned upside down."
You know that 起きる means "to wake up." This word, however, means to occur. Think of it this way. When an action "wakes up" in a way it is occurring as well. That's why this word means to occur. Just imagine a core (こる) of uranium just occurring out of nowhere to help you to remember this word.
The reading is the same as what you learned with the kanji and the same as 起きる too, meaning you should be able to put together the reading on your own.