Noun[edit] malapropism â(plural malapropisms) (uncountable) The blundering use of an absurdly inappropriate word or expression in place of a similar-sounding one.
Definition of positron. : a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron âcalled also antielectron.
A positron emission tomography (PET) scan is a type of imaging test. It uses a radioactive substance called a tracer to look for disease in the body. A PET scan shows how organs and tissues are working. This is different than magnetic resonance imaging (MRI) and computed tomography (CT), which show the structure of, and blood flow to and from organs.