right-hand

adjective

1. on the right.
2. of, for, or with the right hand.
3. most reliable, valuable, or useful, as a helper or assistant.
4. plain-laid.
5. Also right-handed. Building Trades.
   1. (of a door) having the hinges on the right when seen from the exterior of the building, room, closet, etc., to which the doorway leads.
   2. (of a casement sash) having the hinges on the right when seen from inside the window.

noun

1. the hand that is on the right side, or the side opposite that where the heart is.
2. the right side, as of a person, especially this side considered as the side of precedence or courtesy.
3. a position of honor or special trust.
4. an extremely efficient or reliable person or, sometimes, tool, especially a person considered as one’s assistant.

adjective (prenominal)

1. of, relating to, located on, or moving towards the righta right-hand bend; this car has right-hand drive
2. for use by the right hand; right-handed
3. right-hand man one’s most valuable assistant or supporter

n.

Old English rihthand; see right (adj.2) + hand (n.). Figurative for “indispensable person,” 1520s; right-hand man first attested 1660s. Right-handed attested from late 14c.