- (humorous) A notional disease characterised by a hyperactive imagination.
- 1937, Michael Terry, Sand and Sun Other dislodged stones, however, convinced us the boys had not suffered from imaginitis…
- 1961, Margaret Elizabeth Mulac, Leisure: Time for Living and Retirement "Just a case of galloping imaginitis! Would you suggest with this nonsense that we go back to peeling potatoes and cooking them over a coal stove?"
- 2004, Jerome Kiely, Heat Not a Furnace (page 40) [T]wo of them look as healthy as mountain sheep, so they are suffering only from imaginitis but the third has trouble lowering herself down the steps so either she has very bad phlebitis or her womb is fallen.