Appears to understand script (5)
I believe the answer is:
seems
'appears' is the definition.
('seem' can be a synonym of 'appear')
'understand script' is the wordplay.
'understand' becomes 'see' ('see' can be a synonym of 'understand').
'script' becomes 'ms' (I've seen this in other clues).
'see'+'ms'='SEEMS'
'to' is the link.
(Other definitions for seems that I've seen before include "Gives a certain impression" , "Appears, looks" .)