This word is occasionally used to refer to a fee (payment) for services rendered by an eminent or professional person. An honorarium is considered a reward for some act for which custom or tact forbids the setting of a fixed amount, or fee: "The ambassador received a small honorarium for speaking at our meeting." The word is a kind of euphemism for fee; an honorarium is not considered a recognition in money so much as a token of the honor conferred by the presence of the person rendering the service.
Dictionary of problem words and expressions. Harry Shaw. 1975.