Restrictive means limiting what someone can do or limiting how something can be used. A restrictive rule narrows your options or prevents certain actions. When a school has a restrictive dress code, it means students can't wear certain types of clothing: maybe no shorts, no hats, or only specific colors. When a doctor puts you on a restrictive diet for medical reasons, you have to avoid certain foods you might normally eat.

The word carries a sense of constraint or confinement. A restrictive contract might prevent a musician from recording with anyone except one particular company. Restrictive laws limit people's choices or freedoms. Sometimes restrictions serve an important purpose: restrictive rules about who can drive keep roads safer. Other times, restrictions feel unnecessarily limiting, like when a game has such restrictive requirements that it's barely fun anymore.

In grammar, a restrictive clause is a phrase that narrows down which specific thing you're talking about. In the sentence “The book that I borrowed from the library is overdue,” the phrase “that I borrowed from the library” is restrictive because it tells you which specific book, not just any book.

The opposite of restrictive is permissive or open: something that allows more freedom and flexibility.