Yesterday I wrote about how the word confessor can refer either to someone who hears or makes a confession. While the word might seem unusual in this regard, there are a surprising number of words in the English language which have contrary meanings. Consider the following sentences:
I must dust before the guests arrive! (remove dust)
The police dusted for fingerprints. (added dust)
We’ve sanctioned (approved) the use of sanctions (penalties) against Russia.
We can weather (withstand) the storm in here.
The rocks were weathered (worn down) over the years.
They’re screening (showing) some great films.
While he got dressed he was screened (hidden) from view.
Such words are known as auto-antonyms (an antonym being a word with the opposite meaning to another), contronyms, or Janus words (the Ancient Roman god often depicted with two faces). How do such words come to be?
A couple of different reasons. One, which is fairly rare, is that two identical words can evolve twice, with two different etymologies, but happen to be identical, and have opposing meanings. An example of this is to cleave, which usually means to separate, but can also mean to bind. The former is from the Old English clēofan, while the latter is from a different Old English word, clifian.
And sometimes, it’s just laziness really. When we change a noun to a verb, we often take the easiest route possible. Need to find a way to refer to removing dust? Oh, let’s just say dust. Need to find a way to refer to adding dust? Dust.
And that generally works fine. In the context, it’s usually clear which meaning is being used. Plus, we use the verb to refer to removing dust more often. If both uses of the word were equally common, we’d probably change one of them (e.g. to dedust) to avoid constant confusion, but we use to dust to mean to add dust so rarely that there’s no need to do anything.
And this is the case with a lot of other auto-antonyms. Languages are amazing, beautiful, complex things, but sometimes, good enough is good enough!