Origin and usage
The adjective crazy comes from the verb or noun ‘craze’ and originally meant diseased or damaged. It was first used to mean ‘insane’ in the 17th century, and this meaning was extended to cover the main meaning in use today.
The use of the adjective crazy to describe someone who is suffering from mental illness is no longer considered acceptable; the Macmillan Dictionary entry includes a note warning that this is ‘a word that may cause offence’. When followed by the preposition ‘about’, crazy‘s meaning changes: to be crazy about someone is to be in love with them, while to be crazy about something is to be very enthusiastic about it. When preceded by a noun, -crazy tells you what someone is extremely enthusiastic about. To be stir-crazy, meanwhile, is to be longing for release from literal or figurative confinement; it was originally used to describe someone who had spent a long time in prison or ‘stir’. Crazy is also a noun used to refer informally to someone who is mentally ill; this meaning is labelled offensive, and the same warning applies as for the use of the adjective in this way. This noun is older than you might think, first recorded in the mid 19th century. A more recent use is recorded in the Open Dictionary: using crazy as a noun to refer to crazy actions or behaviour. Crazy is also used as an adverb to mean ‘extremely’. This too is older than you might think, being first recorded in the late 19th century. Crazy occurs in a number of compounds, including crazy paving, crazy golf and crazy quilt, an American term for what in British English is called a patchwork quilt.
“Daisy, Daisy, give me your answer, do! I’m half crazy, all for the love of you!”
(Harry Dacre, Daisy Bell (song))
bananas, barmy, batty, bonkers