the most important or powerful person
最も重要で力のある人物 (mottomo juuyou de chikara no aru jinbutsu)
"He’s the top dog in the company."
"彼は会社で最も重要な人物です。" (kare wa kaisha de **toppu doggu** desu)
The most important part of the economy.
to help someone in trouble
to depart for a destination
Being too inquisitive can lead to trouble.
to campaign for a political position
to have sympathy for someone