Emily Dickinson Lexicon

COL-LAT'ER-AL, a. [L. collateralis; con and lateralis, from latus, a side.]

1. Being by the side, side by side, on the side, or side to side. In his bright radiance and collateral light Must I be comforted, not in his sphere. – Shak. Collateral pressure is pressure on the side. So we say, collateral circumstances, circumstances which accompany a principal event.
2. In genealogy, descending from the same stock or ancestor, but not one from the other; as distinguished from lineal. Lineal descendants proceed one from another in a direct line; collateral relations spring from a common ancestor, but from different branches of that common stirps or stock. Thus the children of brothers are collateral relations, having different fathers, but a common grandfather. – Blackstone.
3. Collateral security, is security for the performance of covenants or the payment of money, besides the principal security.
4. Running parallel. – Johnson.
5. Diffused on either side; springing from relations; as, collateral love. – Milton.
6. Not direct, or immediate. If by direct or collateral hand. – Shak.
7. Concurrent; as, collateral strength. – Atterbury.