Stretchy and Expandable Cord Used in Waistbands
Puzzle 4 of Auction House Hard Pack
Question is: Stretchy and Expandable Cord Used in Waistbands
and the answer is: ELASTIC
Word Meaning:
ELASTIC — Capable of stretching; particularly, capable of stretching so as to return to an original shape or size when force is released.
Definitions from Wiktionary.