preclude

Preclude is a verb that means to prevent something from happening or to rule it out in advance. It can indicate making an outcome impossible, or excluding a possibility by circumstance, rule, or agreement. The word is often used with a direct object and the prepositional phrase from, as in “preclude someone from doing something,” or in a more general sense, as in “This policy precludes any further action.”

Etymology-wise, preclude comes from Latin praecludere, formed from prae- meaning before and cludere meaning to shut. The term entered English with a sense of closing off or shutting out possibilities, and it has retained that formal, somewhat legal or technical undertone in contemporary use.

Usage notes and examples help distinguish preclude from similar terms. Preclude tends to emphasize the resulting impossibility or exclusion caused by some authority, condition, or rule. For instance, “The contract precludes the parties from pursuing additional litigation” implies that the agreement itself prevents future claims. In everyday language, it can describe physical or practical barriers, such as, “His injury precludes him from participating.” The noun form preclusion is common in formal or legal writing and refers to the act of precluding or the state of being precluded, as in doctrines of preclusion that bar certain claims or defenses.

In summary, preclude conveys a formal sense of preventing or ruling out a possibility, often due to an established rule, condition, or prior action, and it is frequently paired with from doing something.