WordWeb Online

1. Stem the flow of
   "close off the gas when you leave for a vacation";
   - shut off
    
2. Isolate or separate
   - shut off
    
3. Block off the passage through
   "We close off the valve";
   - shut off, block off

Derived forms: closing off, closed off, closes off

Type of: bar, barricade, block, block off, block up, blockade, cease, discontinue, divide, give up, lay off, quit, separate, stop, surcease [archaic]