1. adjective /iˈlæs.tɪk,əˈlæstɪk/
a) Capable of stretching; particularly, capable of stretching so as to return to an original shape or size when force is released.
The rope is somewhat elastic, so expect it to give when you pull on it.
b) Made of elastic.
elastic band
2. noun /iˈlæs.tɪk,əˈlæstɪk/
a) An elastic material used in clothing, particularly in waistbands and cuffs.
Running shorts use elastic to eliminate the need for a belt.
b) An elastic band.
Wikipedia foundation.