appendagen.1. Something appended to, or accompanying, a principal or greater thing, though not necessary to it, as a portico to a house.()Modesty is the appendage of sobriety. (Jer. Taylor.)2. (Biol.) A subordinate or subsidiary part or organ; an external organ or limb, esp. of the articulates.()Antenn and other appendages used for feeling. (Carpenter.)()