pin down pin down /pɪn daʊn/

verb

1. () Define clearly  ( nail down , peg down [Informal] , narrow , narrow down , pin down , specify )
   define clearly
    I cannot narrow down the rules for this game
   I cannot narrow down the rules for this game
   
2. Attach with or as if with a pin  ( pin down , pin up )
   attach with or as if with a pin
    Pin up a picture
   pin up a picture
   
3. Place in a confining or embarrassing position  ( pin down , trap )
   place in a confining or embarrassing position
    He was trapped in a difficult situation
   He was trapped in a difficult situation