
What is a contronym?
Also called antagonyms, autoantonyms, or Janus words, contronyms are words with two definitions that contradict—or are the reverse of—each other. Put another way, “a contronym is a word with a homonym (another word with the same spelling but different meaning) that is also an antonym (a word with the opposite meaning),” according to Grammarly. Read on to enter the mind-blowing world of words that are their own opposites. And speaking of, these words mean the exact opposite of what you think.

Strike
Most people would automatically define the word “strike” as ‘to hit or deliver a blow.’ But in baseball, it can also mean ‘to miss while trying to hit.’

Seed
If you ‘seed the lawn,’ you are adding seeds to the grass. But ‘seeding a watermelon’ means that you are removing the seeds, instead. Want more word nerd trivia? These 15 common words used to mean completely different things.

Trim
When you trim the Christmas tree, are you adding its decorations or removing its branches? Technically, this term can be defined either way.

Bound
Being bound for something means you are moving towards it. But being bound by something means your actions are restrained or limited. Grammar geeks, beware: These 10 words don’t mean anything close to what they sound like, either.

Fast
Fast could mean either ‘secured in one place’ or ‘moving quickly.’ For example, you’d probably want your car to be fast, but the tires to hold fast.

Clip
Beware of the verb “to clip” as well. You can clip papers by fastening them together with a paperclip, or clip a hedge by removing its branches with shears.

Sanction
While a government can ‘sanction’ or allow an event to happen, it can also ‘sanction’ or impose a ban on another country.

Screen
If what you mean is ‘to hide’—as in, ‘a screen of fog’—then using the verb “screen” would be correct. But it’s also correct to use this term in the phrase ‘to screen a movie,’ which would mean ‘to show.’

Weather
Weather can mean ‘to withstand or endure,’ as in ‘weather a storm,” but also ‘worn down,’ as in ‘the rock is weathered.’

Bolt
Are you bolting from the car, or are you bolting the door? The distinction is important: The first usage means ‘to separate by running away,’ and the second means ‘to hold together’ (such as with a bolt).

Consult
Consulting can mean both to give advice and to get advice. While most of us would consult a dictionary or doctor for instructions, a consultant could issue that guidance.

Custom
A custom is a common practice or tradition shared by many people. But it can also refer to one unique item, such as a custom-made blouse.

Dust
When used as a verb rather than a noun, the word “dust” has two opposite meanings: To sprinkle a fine powder over something, or to clean that object by brushing away the dust, instead.

Finished
Finished can mean either completed or destroyed, such as in the sentence, “I am finished.” These 10 words mean very different things in England and America, too.

Out
Used in a phrase like “the stars are out,” the term means the stars are visible. But saying “the lights are out” would mean they are not working, or invisible.

Off
This is another tricky word to watch out for. “Off” can mean both ‘not functioning,’ as well as ‘functioning,’ depending on how it’s used. Try this brain-busting sentence: You should turn off the alarm that is going off.

Overlook
Overlook can mean to monitor or supervise, but it can also mean to neglect or fail to notice. For example, a group of lawyers would not want to overlook an important detail when they overlook the proposed contract.

Left
Asking “Who’s left?” is a complicated question. It could either mean who is remaining or who has departed. People also say these 15 words aren’t words—but they are.

Resign
While “resign” is considered a contronym in writing, it doesn’t work if you say the word out loud. “Resign,” which means ‘to quit,’ is spelled the same as “resign,” which means ‘to sign up again.’ The only catch? The words have two different pronunciations.

Toss out
In a sentence like “I will toss out the idea,” toss out can mean either ‘to suggest’ or ‘to dispose of.’ By the way, you’re probably using these 70 words and phrases all wrong, too.