1.
Third-degree burns are very severe, destroying tissue under the skin.
He suffered ~ burns over 98 per cent of his body.
ADJ: ADJ n
2.
If you say that someone has been given the third degree, you mean that they have been questioned or criticized extremely severely, sometimes with physical violence. (INFORMAL)
The next thing you know, she’s phoned to complain and you’re suddenly being given the third degree.
N-SING: usu the N