Libellus

Libellus is a Latin noun meaning a small book, booklet, or pamphlet. It derives from liber, "book," with the diminutive suffix -ellus, signaling a compact work. Grammatically, libellus is masculine and belongs to the second declension (nom. sing. libellus; gen. sing. libelli).

In classical and late antique Latin, the term could designate any brief written work, including short treatises, notes, letters, or official records. Its emphasis is brevity and portability; a libellus might be a pocket-sized compilation used for personal reference or an administratively issued document such as a petition or certificate.

From the medieval period onward, libellus becomes a common designation for pamphlets and short tracts in scholarly and legal contexts. It also appears as part of book titles to signal a concise or elementary discussion, such as "Libellus de ..." The word persists in modern scholarly Latin as a generic label for compact works and is encountered in bibliographic descriptions of historical texts.

Today, the term is primarily of linguistic and historical interest, used to describe the form and function of abbreviated written works in Latin literature and archival sources.