The term imbecile was once used by psychiatrists to denote a category of people with moderate to severe intellectual disability, as well as a type of criminal. The word arises from the Latin word imbecillus, meaning weak, or weak-minded. It originally referred to people of the second order in a former and discarded classification of intellectual disability, with a mental age of three to seven years and an IQ of 25–50, above "idiot" and below "moron". In the obsolete medical classification, these people were said to have "moderate mental retardation" or "moderate mental subnormality" with IQ of 35–49, as they are usually capable of some degree of communication, guarding themselves against danger and performing simple mechanical tasks under supervision.