A Roman cross? (3)
I believe the answer is:
ten
'a roman cross' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?
'cross' is the wordplay.
I cannot really see how this works, but
'cross' could be 't' (shape) and 't' is located in the answer.
The remaining letters 'en' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ten that I've seen before include "Base of decimal system" , "Cardinal number" , "Half a score" , "X-WORD" , "time" .)