Moved under a clipper at right angles (13)
I believe the answer is:
perpendicular
'at right angles' is the definition.
(I've seen this before)
'moved under a clipper' is the wordplay.
'moved' is an anagram indicator.
'under'+'a'+'clipper'='underaclipper'
'underaclipper' with letters rearranged gives 'PERPENDICULAR'.
(Other definitions for perpendicular that I've seen before include "Style of late English Gothic church architecture" , "Gothic style following 7" , "Like this answer [1A], relative to 1 dn" , "Sort of architecture" , "At ninety degrees" .)