What does impossible mean?
Impossible describes something that cannot be done, happen, or exist. In strict usage, it refers to a clear logical or practical impossibility: a result may be impossible because it contradicts the laws of nature or because the available means cannot produce it. More informally, the word is used for exceptionally difficult tasks, such as an impossible puzzle, an impossible deadline, or an impossible situation. It can also describe something so extreme that it appears beyond ordinary experience. The adjective is especially natural in expressions such as "seemingly impossible," "virtually impossible," and "an impossible task." In everyday speech, people sometimes use it to mean merely very difficult, but "extremely difficult" or "virtually impossible" can express the same idea more precisely. As a noun, "the impossible" can refer to what cannot be achieved or imagined, especially within a larger philosophical or artistic context.
Incapable of being done, happening, or existing; not possible.
"It is impossible to predict exactly how the election will be resolved."
Can also be used informally for something extremely difficult or undesirable.
Something that cannot be achieved, experienced, or imagined.
"The campaign asks its supporters to attempt the impossible."
Usually appears in the phrase "the impossible" and has a rhetorical or philosophical tone.
The word impossible contains its own negation: what cannot be done is, by definition, not possible.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does impossible come from?
The word comes from late Middle English and was formed in the same way as other adjectives ending in -able, using the Latin prefix im- and the stem posse, meaning "to be able." Its immediate Latin ancestor was impossibilis, meaning "not possible" or "cannot be done." The modern English adjective developed during the Middle English period and retained the sense of being beyond the power or possibility of achieving something.
Related word forms
How impossible is actually used
The word is common in both formal and informal contexts. It can express a literal logical impossibility or, more loosely, describe a task that is extremely difficult; phrases such as "virtually impossible" and "seemingly impossible" are especially common.
Easily confused with impossible
Impossible means that something cannot happen or be done, whereas improbable means that it is very unlikely, though still possible.