Definition of collateral

• a. - Coming from, being on, or directed toward, the side; as, collateral pressure.
• a. - Acting in an indirect way.
• a. - 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.
• a. - Tending toward the same conclusion or result as something else; additional; as, collateral evidence.
• a. - Descending from the same stock or ancestor, but not in the same line or branch or one from the other; -- opposed to lineal.
• n. - A collateral relative.
• n. - Collateral security; that which is pledged or deposited as collateral security.