1) Cord for fastening 2) Cord for opening a door 3) Opener 
• (n.) A string for raising the latch of a door by a person outside. It is fastened to the latch and passed through a hole above it in the door.
Latch'string` noun A string for raising the latch of a door by a person outside. It is fastened to the latch and passed through a hole above it in the door. To find the latchstring out , 
[n] - opener consisting of a string that can be passed through a hole in a door for raising the latch from outside
noun opener consisting of a string that can be passed through a hole in a door for raising the latch from outside