(idiomatic) by the way; now that I think about it; indicates something brought to mind.

(idiomatic) To reconsider, use judgement; to proceed with caution or thought.

(transitive) To change one's mind concerning, especially to decide against.

(idiomatic) To ponder or reflect on a subject.

(idiomatic, euphemistic) Clipping of close one's eyes and think of England and its variants.

(idiomatic) To create in one’s mind; to invent.

(often derogatory) An in-depth article that discusses a topic thoroughly and elaborates the writer's point of view, to inspire deep thought related to the article's subject.

(transitive, idiomatic) To have a very high opinion of; to have a strong attachment to or affection for.

Alternative spelling of think tank

To perform research and develop recommendations as part of a think tank.