QUATRAIN, sometimes spelt Quartain (from Fr. quatre, four), a piece of verse complete in four rhymed lines. The length or measure of the verse is immaterial, but they must be bound together by a rhyme-arrangement. This form has always been popular for use in the composition of epigrams, on account of its brevity and neatness, and may be considered as a modification of the Greek or Latin epigram at its concisest.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)