1. intensive questioning or rough treatment, esp. by the police, in order to get information or a confession.
2. the degree of master mason in Freemasonry.
Pronunciation: (thûrd'di-grē'), [key]
—v., -greed, -gree•ing,
to subject to the third degree.
of or pertaining to the third degree.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.