shelf 
/ˈʃɛlf/ noun
plural shelves /ˈʃɛlf/ noun /ˈʃɛlvz/ [count] 1 : a flat board which is attached to a wall, frame, etc., and on which objects can be placed
▪ Put the vase on the shelf. ▪ the top/bottom shelf of the kitchen cabinet ▪ Will you get that book down off the shelf? ▪ We don't have much shelf space. — see also bookshelf 2 geology : a flat area of rock, sand, etc., especially underwater
▪ a coastal shelf — see also continental shelf
▪ Put the vase on the shelf. ▪ the top/bottom shelf of the kitchen cabinet ▪ Will you get that book down off the shelf? ▪ We don't have much shelf space. — see also bookshelf
▪ a coastal shelf — see also continental shelf
off the shelf
: directly from a store without having to be specially made or ordered
▪ The dress was a perfect fit right off the shelf. ▪ equipment purchased off the shelf
▪ The dress was a perfect fit right off the shelf. ▪ equipment purchased off the shelf
on the shelf
: in an inactive state : not active or being used
▪ They put their plan to remodel the house on the shelf for the time being. ▪ The quarterback remains on the shelf [=is still not playing] with a severe injury.
▪ They put their plan to remodel the house on the shelf for the time being. ▪ The quarterback remains on the shelf [=is still not playing] with a severe injury.
