Epigram
2 of the 7 encyclopedias on this shelf carry an entry for Epigram. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
ep'i-gram, originally, an inscription placed on a tomb, temple doorway, statue, or triumphal arch. Naturally, bright sayings were chosen for such a purpose. The term has come to mean a bright thought tersely expressed, usually with a turn of wit. Words are used a little out of the ordinary meaning so as to create surprise. In general, any pungent way of saying a good thing is said to be epigrammatic. A good pun is an epigram. Many proverbs are epigrams. A few well worn examples are added: Language is the art of concealing thought. He was conspicuous by his absence. When you have nothing to say, say it. The obedient wife commands her husband. Sweet are the uses of adversity. Beauty when unadorned is adorned the most. The more we have, the less we spend. He is the richest who is content with the least. The more busy we are, the more leisure we have. The fastest colors are those that won't run. The best way to contract debts is to pay them off. The misfortunes hardest to bear are those that never come. Under this stone my wife doth lie; She is at rest, and so am I.
Collier's New Encyclopedia (1921)
a short poem of a pointed or antithetical character, or any short composition expressed neatly and happily or antithetically. Epigram was the name given by the Greeks to a poetic inscription on a public monument, and hence the word came parsed into its modern signification. Of the Roman poets, Catullus and Martial are most celebrated for their epigrams. In cookery, epigrams of mutton, veal, etc., are small cutlets of mutton, veal, etc., dressed in a particular manner.