(biology) The reactivity of blood serum, especially to a virus.

Any of several bivalve molluscs that are a source of pearls, but especially Pinctada margaritifera.

Alternative spelling of de-escalate

Expresses regret, remorse, or sorrow. / Used as a request for someone to repeat something not heard or understood clearly. / Used to correct oneself in speech. / Said as a request to pass somebody.