rule out

When considering an idea or possibility, to rule it out is to decide it cannot be true or happen.

Often used in negative forms such as “cannot rule out” to say that something remains possible because the evidence does not exclude it. In other contexts, it can mean deciding that someone or something is unsuitable or no longer under consideration.

• With so little data, we can’t rule out the possibility of life beneath the ice.
• That signal is weak, but we shouldn’t rule out a natural explanation.
• Until the samples are tested, researchers cannot rule out contamination.