appendage Definition

1. Anything added or attached to a larger or more important part.

Thesaurus: addition, attachment, supplement, addendum, adjunct.
2. zool.
A part or organ, eg a leg, antenna, etc, that extends from the main body of animals such as insects, crustaceans, etc.
Thesaurus: limb, member, extremity, prosthesis.
3. bot.
An offshoot, eg a branch, leaf, etc, that sprouts from the stem of a plant.