The term 'third degree' is often used to refer to a harsh or intense questioning or INTERROGATION. The crossword solutions for this term include 'GRILL' (5 letters), 'QUESTION' (8 letters), 'INQUIRY' (7 letters), 'TEST' (4 letters), 'INVESTIGATION' (13 letters), 'EXAMINATION' (11 letters), 'DOCTORATE' (9 letters), 'GRILLING' (8 letters), 'INTERROGATION' (13 letters), and 'PHD' (3 letters). All of these words are related to the idea of intense questioning or INVESTIGATION, which is what the term 'third degree' typically refers to.