non concessit (non k<<schwa>>n-ses-it), n.[Law Latin “he did not grant”] Hist. 1.English law. The plea by which the defendant denies that certain rights were given by letters patent to the plaintiff. • For example, if a plaintiff sues for the infringement of a patent right, the defendant can deny that the Crown granted the plaintiff that right as alleged in the plaintiff’s declaration. 2. A plea by a stranger to a deed, by which the title and operation of the deed are placed in issue.

[Blacks Law 8th]