prevent, forestall, foreclose, preclude, forbid

keep from happening or arising; have the effect of preventing; "My sense of tact forbids an honest answer"

• save, make unnecessary — make unnecessary an expenditure or effort
• debar, obviate, deflect, avert, head off, stave off, fend off, avoid, ward off — prevent the occurrence of; prevent from happening
• obstruct, blockade, block, hinder, stymie, stymy, embarrass — hinder or prevent the progress or accomplishment of
• thwart, queer, spoil, scotch, foil, cross, frustrate, baffle, bilk — hinder or prevent (the efforts, plans, or desires) of
• stop, halt, block, kibosh — stop from happening or developing