1. (v.) To block or prevent; to frustrate; as, to thwart an attempted change; to thwart a rebellion\.

2. (a.) Fig.: Perverse; crossgrained.

3. (a.) Thwartly; obliquely; transversely; athwart.

4. (prep.) Across; athwart.

5. (n.) A seat in an open boat reaching from one side to the other, or athwart the boat.

6. (v. t.) To move across or counter to; to cross; as, an arrow thwarts the air.

7. (v. t.) To cross, as a purpose; to oppose; to run counter to; to contravene; hence, to frustrate or defeat.

8. (v. i.) To move or go in an oblique or crosswise manner.

9. (v. i.) Hence, to be in opposition; to clash.

across across the grain annul athwart athwartships baffle balk beat bench bendwise bias biased biaswise bilk blast block brace brave bring to nothing buffer cancel cancel out cast down catercorner catercornered challenge check checkmate circumvent come to nothing confound confront contrariwise contravene contrawise counter counteract counterbalance countermand counterwork crisscross cross cross-grained crossing crossway crossways crosswise curb dash defeat defeat expectation defy destroy diagonal disappoint discomfit disconcert discountenance dish disillusion disrupt dissatisfy elude flummox foil foul up frustrate gum up hinder impede invalidate kittycorner knock the chocks let down negate negativate negative neutralize nonplus nullify oblique obliquely obstruct offset oppose overthwart perplex queer restrain ruin sabotage scotch short-circuit sideways sidewise slant spike spoil stonewall stop stultify stump style stymie tantalize tease thwartly thwartways transversal transverse transversely traverse undo upset vitiate void