thwart

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To prevent the occurrence, realization, or attainment of: They thwarted her plans.
2. v. To oppose and defeat the efforts, plans, or ambitions of.
3. n. Nautical A seat across a boat on which a rower may sit.
4. adj. Extending, lying, or passing across; transverse.
5. adj. Eager to oppose, especially wrongly; perverse.
6. adv. Archaic Athwart; across.

Century Dictionary and Cyclopedia

1. n. See the extract.
2. From side to side; across; crosswise; transversely; athwart.
3. Across; athwart.
4. Opposite to; over against.
5. Lying or extending across or crosswise; cross; transverse.
6. Antithetical.
7. Perverse; contrary; cross-grained.
8. n. Opposition; defiance.
9. To pass over or across; cross.
10. To put crosswise, or one across another.
11. To put in the way; oppose.
12. To cross, as a purpose; contravene; frustrate; baffle.
13. Synonyms Foil, Baffle, etc. See frustrate.
14. To go crosswise or obliquely.
15. To be in opposition; be contrary or perverse; hence, to quarrel; contend.
16. n. A seat across a boat on which the oarsman sits. A thwart is usually a special fixture, but a board may be used for the purpose. Some thwarts are contrived to slide backward and forward with the movements of the oarsman, as in light sculls or shells used for rowing exercise or for racing.

Wiktionary

1. v. transitive to prevent; to halt; to cause to fail; to foil; to frustrate.
2. n. nautical A brace, perpendicular to the keel, that helps maintain the beam (breadth) of a marine vessel against external water pressure and that may serve to support the rail.
3. n. nautical A seat across a boat on which a rower may sit.

GNU Webster's 1913

1. adj. Situated or placed across something else; transverse; oblique.
2. adj. obsolete Fig.: Perverse; crossgrained.
3. adv. obsolete Thwartly; obliquely; transversely; athwart.
4. prep. Across; athwart.
5. n. (Naut.) A seat in an open boat reaching from one side to the other, or athwart the boat.
6. v. obsolete To move across or counter to; to cross.
7. v. To cross, as a purpose; to oppose; to run counter to; to contravene; hence, to frustrate or defeat.
8. v. rare To move or go in an oblique or crosswise manner.
9. v. rare Hence, to be in opposition; to clash.

WordNet 3.0

1. v. hinder or prevent (the efforts, plans, or desires) of
2. n. a crosspiece spreading the gunnels of a boat; used as a seat in a rowboat