c.1300, "formal written statement," especially, in civil law, "plaintiff's statement of charges" (mid-14c.); from O.Fr. libelle (fem.), from L. libellus "a little book, petition," dim. of liber "book" (see library). Broader sense of "any published or written statement likely to harm a person's reputation" is first attested 1630s. The verb is c.1570, from the noun. Related: Libelous; libellous.