If "broad" refers to width:
* Narrow
* Slim
* Thin
* Tight
If "broad" refers to scope or range:
* Narrow
* Limited
* Restricted
* Specific
If "broad" refers to a general term:
* Specific
* Detailed
* Precise
If "broad" refers to a woman (slang):
* Man (although this can be considered offensive)
* Gentleman
* Guy
Please provide more context so I can give you the most accurate antonym.