Weakened

Weakened is the past participle of the verb weaken and an adjective describing something that has lost strength, power, or effectiveness. It denotes a reduction in force, quality, or intensity, and is used across physical, mechanical, and abstract contexts.

As a verb, weaken can be transitive or intransitive. For example, a storm can weaken as it moves inland, a policy can weaken an institution’s authority, and a material may weaken from corrosion. The form weakened appears in past tense or in participial phrases, as in "The bridge was weakened by years of neglect."

As an adjective, weakened describes a state of reduced strength: a weakened immune system, weakened brakes, a weakened signal. In everyday language, it can refer to anything from a sauce that has been thinned by added liquid to economic conditions described as a weakened market.

In medical and scientific contexts, weakened often appears in two related ways. One, to describe organisms or substances with reduced virulence or activity. Two, in vaccines, where a weakened or attenuated pathogen is used to provoke an immune response without causing serious disease. Attenuated vaccines are common for several diseases but require careful handling and monitoring for safety.

Common synonyms include diminish, reduce, and debilitate; antonyms include strengthen and reinforce. The word is frequently used with prepositional phrases such as weakened by, weakened state, or weakened condition.