| 1. | a support, as of metal or wood, projecting from a wall or the like to hold or bear the weight of a shelf, part of a cornice, etc. |
| 2. | a shelf or shelves so supported. |
| 3. | Also called square bracket. one of two marks [ or ] used in writing or printing to enclose parenthetical matter, interpolations, etc. |
| 4. | Mathematics.
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| 5. | a grouping of people based on the amount of their income: the low-income bracket. |
| 6. | a class; grouping; classification: She travels in a different social bracket. |
| 7. | Architecture.
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| 8. | (on a staircase) an ornamental piece filling the angle between a riser and its tread. |
| 9. | Shipbuilding.
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| 10. | a projecting fixture for gas or electricity. |
| 11. | Gunnery. range or elevation producing both shorts and overs on a target. |
| 12. | to furnish with or support by a bracket or brackets. |
| 13. | to place within brackets; couple with a brace. |
| 14. | to associate, mention, or class together: Gossip columnists often bracket them together, so a wedding may be imminent. |
| 15. | Gunnery. to place (shots) both beyond and short of a target. |
| 16. | Photography. to take (additional shots) at exposure levels above and below the estimated correct exposure. |

| square bracket n. One of a pair of marks, [ ], used to enclose written or printed material or to indicate a mathematical expression considered in some sense a single quantity. |