from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
THIRD PARTIES. This term includes all persons who are not parties to the
contract, agreement or instrument of writing, by which their interest in the
thing conveyed is sought to be affected. 1 N. S. 384. See also 2 L. R. 425 6
M. R. 528.
2. But it is difficult to give a very definite idea of third persons,
for sometimes those who are not parties to the contract, but who represent
the rights of the original parties, as executors, are not to be considered
third person. See Duverg. tome 16, n. 34, 35, 36, et idem, tome 17, n. 190;
2 Bouv. Inst. n. 1335, et seq.