What is the meaning of Thwart?

Placed or situated across something else; cross, oblique, transverse.

Of people: having a tendency to oppose; obstinate, perverse, stubborn.

Of situations or things: adverse, unfavourable, unlucky.

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

Across, athwart.

To cause to fail; to frustrate, to prevent.

To place (something) across (another thing); to position crosswise.

To hinder or obstruct by placing (something) in the way of; to block, to impede, to oppose.

To move (something) across or counter to; to cross.

A seat across a boat on which a rower may sit.

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.

An act of thwarting; something which thwarts; a hindrance, an obstacle.

Source: wiktionary.org