treatise Copy link Outline 1. lĭber, lĭbellus (Kr.).2. *dissertātio, dispŭtātio (both strictly denoting verbal discussion, but used freely by modern Latinists to denote written compositions). • treatise: 1. lĭber, lĭbellus (Kr.). 2. *dissertātio, dispŭtātio (both strictly denoting verbal discussion, but used freely by modern Latinists to denote written compositions).