Green’s Dictionary of Slang

desperate n.

(Aus.) joc. ref. to racetrack attendees (ie.e desperate for a win).

[Aus]J. Byrell Lairs, Urgers & Coat-Tuggers 148: [He was] seldom - if ever - off the bullseye when it came to his instant character assessments, especially with the desperates and runaway slaves who habitually attend neddy meetings.