Definition - A figure of speech where understatement is used to increase emphasis.

Example -
Always referring to your amputated arm as "my inconvenience."

Etymology -
The word was taken directly from the Greek where it means "lessening" (from the Greek meion, less).

Oxford English Dictionary -
Its first citation is from 1586:
"Meiosis, a manner of disabling, as when we say, Alas Sir, it is not in my power to doe it."
(A. Day, Eng. Secretary ii. (1625), 84)

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