As a noun, it means a person who publicly supports or speaks in favor of a cause, person, or idea. As a verb, it means to actively support or argue for something.
From Latin *advocatus* “one called to aid, legal assistant,” from *advocare* “to call to one’s aid,” from *ad-* “to” and *vocare* “to call.” It first referred to legal helpers before broadening to general support.
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