noun a collateral relative.
2. collateral ·adj acting in an indirect way.
3. collateral ·adj coming from, being on, or directed toward, the side; as, collateral pressure.
4. collateral ·noun collateral security; that which is pledged or deposited as collateral security.
5. collateral ·adj tending toward the same conclusion or result as something else; additional; as, collateral evidence.
6. collateral ·adj descending from the same stock or ancestor, but not in the same line or branch or one from the other;
opposed to lineal.
7. collateral ·adj related to, but not strictly a part of, the main thing or matter under consideration; hence, subordinate; not chief or principal; as, collateral interest; collateral issues.