主しゅ控びかえ

noun

mainstay; key person; central figure

Refers to a person who plays a central supporting role in a group or organization, often behind the scenes.

• 彼かれはチームの主しゅ控びかえとして、いつも陰かげで支ささえている。

  He always supports the team from behind the scenes as its mainstay.

• あの部ぶ署しょの主しゅ控びかえは彼かの女じょだと言いわれている。

  She is said to be the key person in that department.