Think - definition of Think from LearnEnglishIrregularVerbs.com

think /θɪŋk/

1 to have a particular opinion or belief:
For some reason, I keep thinking it's Sunday today.
I thought I heard you calling my name.
I think this is her scarf, but I'm not sure.
People think he is one of the greatest jazz musicians of all time.
2 to use your mind to consider or understand something, to form connected ideas, to try to solve problems, etc:
He could only accept the pictures that were flooding into his mind, without attempting to think what they meant.
He thought for a few seconds and then wrote: "I won't be home for a few days. I'm going away".
I thought about my meeting with Bert.
3 to have ideas, words or images in your mind:
I was just thinking what a wonderful summer it was.
There was a second when the look on his face showed what he was thinking.
Even when he left he was still thinking about renting the room.