restrict

Formsrestricts, restricting, restricted

1. 1
   verbtransitive

   To hold something within set boundaries; to limit or confine it.

   The city restricts parking on these streets during snowstorms.

   Strict visa policies restrict how long visitors may stay.

   Similarlimit, restrain, confine, curb, constrain

   Oppositeallow, permit, expand

   Note

   Its Latin source pictures a cord pulled taut: restringō meant "draw back tightly," from re- "back" and stringō "press, tighten." The usual construction is restrict something to something. A patient is restricted to rice and cold meat, and a football side is restricted to shooting from long range. Here to names the narrow space that is left over, not a destination.

2. 2
   verbtransitive

   To treat a function as defined only on a smaller part of its original domain.

   Mathematicians often restrict a function to an interval where it is one-to-one.

   When we restrict the mapping to the unit circle, its behavior becomes simpler.

   Oppositeextend

   Note

   Mathematicians use the verb for shrinking a function's domain while keeping its rule. Each remaining input gives the same value as before, but fewer inputs are allowed. The classic case is sine, which repeats its values endlessly. Restrict it to the interval from −π/2 to π/2 and each value occurs only once, so an inverse can be defined. As with the everyday sense, the construction is restrict something to a set.

3. 3
   adjectiveobsolete

   Held within bounds; limited or confined.

   Note

   An obsolete adjective that carried the Latin participle restrictus straight into English, compared as more restrict and most restrict. The participle restricted has since taken over the job, so a modern writer should use that form. The same Latin source also produced ristretto, a doublet of this adjective.

Showing meanings only. Show all 3