The demonyms of Toowoomba include Toowoombian, Toowoomban and Toowoombarite which are sometimes used to reference the city of Toowoomba and its residents.
For the uninitiated, a demonym is a word that identifies residents or natives of a particular place and is usually derived from the name of the place.
So essentially a person who comes from Toowoomba could, for example, be called a Toowoombarite.
Further reading: Demonym on Wikipedia
