(1):

(n.) An effusion of wit; a bright thought tersely and sharply expressed, whether in verse or prose.

(2):

(n.) The style of the epigram.

(3):

(n.) A short poem treating concisely and pointedly of a single thought or event. The modern epigram is so contrived as to surprise the reader with a witticism or ingenious turn of thought, and is often satirical in character.