Definition of: collateral

(kə·lat′ər·əl) adjective
1. Subordinately connected; attendant or secondary; incidental.
2. Corroborative; confirmatory.
3. Being or lying alongside; parallel; bordering.
4. Descended from the same ancestor in a different line: distinguished from lineal.
5. Pertaining to property, as stocks or bonds, deposited as security additional to one's personal obligation: a collateral note. See synonyms under INCIDENTAL.
—noun
1. Collateral security, which in case of default, is subject to immediate forfeiture, without recourse to legal proceedings. See COLLATERAL SECURITY.
2. A kinsman or kinswoman descended from the same ancestor in a different line.
3. An accompanying or subordinate fact, condition, or part.
4. Anat. A part connected with or derived from a main branch: the collaterals of a nerve fiber. See synonyms under SECURITY. [<Med. L collateralis <com- together + lateralis lateral <latus, -eris side]
—col·lat′er·al·ly adverb