factum

[L. See Fact.]

1. (Law) A man's own act and deed; particularly: (a) (Civil Law) Anything stated and made certain. (b) (Testamentary Law) The due execution of a will, including everything necessary to its validity.

2. (Mach.) The product. See Facient, 2.

[Latin, Fact, act, or deed.] A fact in evidence, which is generally the central or primary fact upon which a controversy will be decided.