(UK) Abbreviation or diminutive for baronet, later replaced by Bt. It is a post-nominative title; the pre-nominative is Sir (e.g. Sir John Smith Bart.).

(physics) A hypothetical source of extreme-energy cosmic rays (EECR), capable of accelerating particles to 1 ZeV (zetta-electronvolt).

(anatomy) A fold of peritoneum separating the right and left lobes of the liver and attaching it to the diaphragm and the anterior abdominal wall.

plural of czarevitch