What does "jingo" mean?

Jingo: A statesman who pursues, or who favors, aggressive, domineering policy in foreign affairs. [Cant, Eng.] Note: This sense arose from a doggerel song which was popular during the Turco-Russian war of 1877 and 1878. The first two lines were as follows: -- We don't want to fight, but by Jingo if we do, We 've got the ships, we 've got the men, we 've got the money too.

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