鈥楾hwart鈥� encompasses two opposing meanings
On one hand, to聽thwart聽something is to hinder or prevent it. But in 1609, building a bridge over a river was described as 鈥渢hwarting a bank.鈥�
On one hand, to聽thwart聽something is to hinder or prevent it. But in 1609, building a bridge over a river was described as 鈥渢hwarting a bank.鈥�
A聽reader asked about the origins of thwart, which has two sets of meanings that are at odds. On one hand, to thwart something is to hinder or prevent it; in older uses, though, thwart implied crosswise motion or position. English has several other words that occupy both of these semi-opposed semantic fields, with meanings converging on 鈥渢o block鈥� and 鈥渢o span.鈥�
English borrowed thwart from Old Norse around the 12th century. It seems to have had a root sense of 鈥渁cross鈥� or 鈥済oing back and forth,鈥� which blossomed into a range of similar meanings. It could mean 鈥渢o traverse鈥� 鈥� Shakespeare has a character 鈥渢hwarting ... the seas.鈥� To thwart also meant 鈥渢o place something across鈥�: In 1609 building a bridge over a river was described as 鈥渢hwarting a bank.鈥� Likewise, the preposition athwart means 鈥渁cross,鈥� as with a bar placed 鈥渁thwart the door鈥� (1470). Since 1736, the noun thwart has referred to the pieces of wood or metal that reinforce the hulls of canoes and boats. 聽
A key effect of placing one thing across another, though, is blockage, and this is the semantic field thwart occupies now. Overwhelmingly today, thwart means to get in the way, or as the Oxford English Dictionary puts it, 鈥渢o foil, frustrate, balk, defeat.鈥澛�
The connection between laying/lying across and blocking is easy to visualize. What鈥檚 surprising is how many common words share it. Cross itself is the most obvious parallel. It also includes spanning and hindering 鈥� the bridge allows people to cross the river; the cartoon villain warns the hero 鈥淒on鈥檛 cross me!鈥澛�
Today the primary meanings of traverse align with the spanning side. According to Merriam-Webster, they are 鈥渢o go or travel across or over鈥� and 鈥渢o lie or extend across.鈥� As a noun, traverses are crosspieces that extend from one side to the other, including ceiling rafters, door lintels, and so on. Most of its earliest senses (14th to 15th century) are of the obstructive variety. A traverse was also a screen or curtain positioned across a room, dividing it; traverses were military earthworks dug to form a barrier to enemy fire. As a verb, it indicated 鈥渢o deny (an allegation) formally; to dispute or challenge.鈥�
Balk has a similar range of senses. In Old English, it was a heap of earth, a ridge between two plowed furrows. By 1400, a balk was an exposed roof beam that stretched from wall to wall. By 1589, 鈥渢o balk鈥� meant to 鈥減lace a balk in front of someone,鈥� i.e., hinder or thwart. If you hindered yourself, so to speak, you hesitated or stopped short and refused to go on, and this is balk鈥檚 primary sense today. (鈥淪he balked at the idea of coming up with a better closing sentence.鈥�)