n.
        - a thin piece of metal with a sharp point at one end and a round head at the other, used for fastening pieces of cloth, paper, etc. 
▸a small brooch or badge.
 ▸Medicine  a steel rod used to join the ends of fractured bones while they heal.
 - a metal peg that holds down the activating lever of a hand grenade, preventing its explosion.
 - a metal projection from a plug or an integrated circuit which makes an electrical connection with a socket or another part of a circuit.
 - Golf  a stick with a flag placed in a hole to mark its position.
 - a skittle in bowling.
 - 
(pins)
 informal legs.
 - Chess  an attack on a piece or pawn which is thereby pinned.
 - Brit. historical a half-firkin cask for beer.
 
v.
 (pins, pinning, pinned)
   - attach or fasten with a pin or pins. 
▸
(pin something on)
 fix blame or responsibility on.
 - hold someone firmly so they are unable to move. 
▸
(pin someone down)
 restrict the actions of an enemy by firing at them.
 ▸
(pin someone down)
 force someone to be specific about their intentions.
 - Chess  hinder or prevent (a piece or pawn) from moving because of the danger to a more valuable piece standing behind it.
 
 
  Phrase
  
    - pin one's ears back
 listen carefully.  - pin one's hopes 
(or faith)
 on
 rely heavily on. 
   
  Etymology
  OE pinn, of W. Gmc origin, from L. pinna ‘point, tip, edge’.