If "broad" refers to width:
* Narrow
* Thin
* Slender
* Restricted
If "broad" refers to scope or range:
* Narrow
* Limited
* Specific
* Restricted
If "broad" refers to a general term:
* Specific
* Detailed
* Precise
If "broad" refers to a woman:
* Slim
* Slender
* Petite
It is important to consider the context to choose the most appropriate antonym.