Appendage

Part of speech: noun (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. Jer. Taylor.

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

Synonyms: Addition; adjunct; concomitant.