Roughly in Latin (5)
I believe the answer is:
circa
'roughly' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for circa that I've seen before include "Costa del Sol city" , "More or less" , "Close to" , "Around (Latin)" , "About, say, a date" .)