(1) Short for viva voce. An oral (spoken) examination, usually involving the examination candidate meeting the examiners face-to-face so they can ask questions about the candidate's dissertation or research findings. Commonly an important part of the examination process for postgraduate research degrees, such as doctorates. Can be a frightening experience as the examiners are likely to be renowned experts in the candidate's field of study.
(2) Blowjob, oral sex. Pun on the word oral. Possibly with a suggetion that a woman is being tried out or tested to see how well she performs.
Q: How did you get on with that blonde from the History Faculty?
A: She passed her viva, but only just. She gives pretty average head.
A: I viva-ed her on our second date. I'm seeing her again on Friday and I'm hoping to access all areas.