latchstring

latchstring is a   Noun

Definition:

[1] 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, to meet with hospitality; to be welcome. (Intrusion is prevented by drawing in the latchstring.) [Colloq. U.S.]

Synonyms: