noun
key to understanding; point of an argument; something to grasp
Often used in the negative phrase とらえどころのない to describe someone or something vague, elusive, or hard to pin down. The affirmative use is less common.
See also: とらえどころのない
彼の話はとらえどころがなくて、何が言いたいのかわからなかった。
His story was so vague that I couldn't tell what he wanted to say.
That person has an elusive personality.