Figures of over-statement and under-statement

Figures of over-statement are done for effect, to emphasize a point you are looking to make, and include:

Hyperbole-Use of exaggerated terms for emphasis or effect.

Example :

His eloquence could split rocks

Auxesis-Reference to something with a name disproportionately greater than its nature (a kind of hyberbole).

Example :

The wound given to my client... (when referring to a scratch)

Litotes-Understatement used deliberately.

Examples:

Running a marathon in under two hours is no small accomplishment.

It isn't very serious. I have this tiny little tumor on the brain. —J.D. Salinger, The Catcher in the Rye

Meiosis -Reference to something with a name disproportionately lesser than its nature (a kind of litotes).

Example :

The scratch my client gave to the plaintiff... (when referring to a sizeable wound)