right-hand man 
noun
An indispensable helper or chief assistant.Calderwood can't help but tackle things head on, though, and he is ably assisted by his right-hand man, whom he refers to as the silent assassin....
- Heath, ably assisted by his right-hand man Guy Rich - now in the Premier's Office - soon became bigger than the unit itself.
- All of a sudden, his right-hand man, former Chief Councilman Kermit walked in, without any warning whatsoever.
- programmist
- program pencil
- program picture
- program register
- program service
- program step
- program symphony
- progrediency
- progredient
- progress
- progress chaser
- progress-chasing
- progression
- progressional
- progressionally
- progressionary
- progressionism
- progressionist
- progressism
- progressist
- progressive
- Progressive Conservative Party
- progressive dinner
- progressive house
- progressive jazz