Green’s Dictionary of Slang

a lower second university degree.

2002		B. Kirkpatrick Wicked Cockney Rhy. Sl. 25: Desmond Tutu a lower second.
2016		Guardian 12 Aug. 🌐 Those who receive a 2:2, and jauntily tell their friends they ‘got a Desmond’ because they are at an age where they still find rhyming slang funny, are generally using banter to disguise mild disappointment.