Expression of support for exam (4)
I believe the answer is:
viva
I believe this is a double definition.
'expression of support' is the first definition.
(as in 'Viva Las Vegas')
'for exam' is the second definition.
(short for 'viva voce', an oral examination)
(Other definitions for viva that I've seen before include "Long live! - oral exam" , "Kind of exam" , "Do well in Italian" , "Hail to the Spaniards" , "Oral examination" .)