The odd item among the options given is "Rhythm" because it does not belong to the category of figures of speech, whereas the other options such as "Euphemism," "Oxymoron," and "Hyperbole" are all figures of speech that are used to create meaning and emphasis in language.
Euphemism is a figure of speech where a mild or indirect word or expression is used instead of one that is considered too harsh or blunt. For example, saying "passed away" instead of "died."
Oxymoron is a figure of speech that combines two contradictory or opposite terms, creating a new and unexpected meaning. For example, "jumbo shrimp."
Hyperbole is a figure of speech that uses exaggerated language to emphasize a point or create a vivid image. For example, "I've told you a million times."
On the other hand, rhythm refers to the pattern of beats or sounds in music or language, and while it is an important aspect of poetry and speech, it is not a figure of speech.