Medical Definition of Quinsy
Quinsy: Not a TV detective but an old word for a peritonsillar abscess.
Whether you call it quinsy or a peritonsillar abscess, it is a collection of pus (an abscess) behind the tonsils that pushes one of the tonsils toward the uvula (the prominent soft tissue dangling from the back of the palate in the back of the mouth).
A peritonsillar abscess is generally very painful. It is usually also associated with a decreased ability to open the mouth.