reins

Noun

• one of a pair of long straps (usually connected to the bit or the headpiece) used to control a horse
• any means of control
  • "he took up the reins of government"
• plural of rein
• The kidneys.
• The lower part of the back.
• The loins.
• The parts of a vault between the crown and the spring or abutment, including, and having especial reference to, the loading or filling behind the shell of the vault.

Verb

• control and direct with or as if by reins
• stop or slow up one's horse or oneself by or as if by pulling the reins
• stop or check by or as if by a pull at the reins
• keep in check
• third-person singular simple present indicative of rein

Synonyms

draw rein, harness, rein, rein in, rule