catgut

Short definition from Wiktionary

Noun

1. 1
   A cord of great toughness made from the intestines of animals, especially of sheep, used for strings of musical instruments, racquets, sutures etc.
2. 2
   The material from which such cords are made.
3. 3
   A sort of linen or canvas, with wide interstices.
4. 4
   Tephrosia virginiana (goat's rue, devil's shoestring).