off the shelf—(usually of clothing ) made in standard sizes and available from stock, in contrast to items made to order (also: off the peg ):
- Few would buy off the shelf clothes if tailor-made clothes were as cheap and as available.
on the shelf—
1. in a state of inactivity or uselessness:
- The question of parliamentary reform could not be perpetually kept upon the shelf.
2. (coll., of a woman) unmarried and unlikely to marry:
- She has run through her chances in the matrimonial market and is now on the shelf.
Note: The expression does not correlate in meaning with the phrase on the rack—tormented by anxiety, worry, etc.:
- The master was on the rack until the Board of Inquiry cleared his character in regard to the collision between his boat and the liner.