\Col*lat"er*al\, a. [LL. collateralis; col- +
lateralis lateral. See {Lateral}.]
1. Coming from, being on, or directed toward, the side; as,
   collateral pressure. ``Collateral light.'' --Shak.
2. Acting in an indirect way.
         If by direct or by collateral hand They find us
         touched, we will our kingdom give . . . To you in
         satisfaction.                         --Shak.
3. 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.
         That he [Attebury] was altogether in the wrong on
         the main question, and on all the collateral
         questions springing out of it, . . . is true.
                                               --Macaulay.
4. Tending toward the same conclusion or result as something
   else; additional; as, collateral evidence.
         Yet the attempt may give Collateral interest to this
         homely tale.                          --Wordsworth.
5. (Genealogy) Descending from the same stock or ancestor,
   but not in the same line or branch or one from the other;
   -- opposed to lineal.
Note: 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.
{Collateral assurance}, that which is made, over and above
   the deed itself.
{Collateral circulation} (Med. & Physiol.), circulation
   established through indirect or subordinate branches when
   the supply through the main vessel is obstructed.
{Collateral issue}. (Law)
   (a) An issue taken upon a matter aside from the merits of
       the case.
   (b) An issue raised by a criminal convict who pleads any
       matter allowed by law in bar of execution, as pardon,
       diversity of person, etc.
   (c) A point raised, on cross-examination, aside from the
       issue fixed by the pleadings, as to which the answer
       of the witness, when given, cannot subsequently be
       contradicted by the party asking the question.
{Collateral security}, security for the performance of
   covenants, or the payment of money, besides the principal
   security,

\Col*lat"er*al\, n.
1. A collateral relative. --Ayliffe.
2. Collateral security; that which is pledged or deposited as
   collateral security.