Appendage

Ap·pend·age

Appendage

n.
  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.
  2. A subordinate or subsidiary part or organ; an external organ or limb, esp. of the articulates. (Biol.)
    Antennæ and other appendages used for feeling.
    — Carpenter.