thwart

Short definition from Wiktionary

Adjective

1. 1
   Placed or situated across something else; cross, oblique, transverse.
2. 2
   Of people: having a tendency to oppose; obstinate, perverse, stubborn.
3. 3
   Of situations or things: adverse, unfavourable, unlucky.

Adverb

1. 1
   Across the direction of travel or length of; athwart, crosswise, obliquely, transversely.

Preposition

1. 1
   Across, athwart.

Verb

1. 1
   To cause to fail; to frustrate, to prevent.
2. 2
   To place (something) across (another thing); to position crosswise.
3. 3
   To hinder or obstruct by placing (something) in the way of; to block, to impede, to oppose.
4. 4
   To move (something) across or counter to; to cross.

Noun

1. 1
   A seat across a boat on which a rower may sit.
2. 2
   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. 3
   An act of thwarting; something which thwarts; a hindrance, an obstacle.