Turns to stare rudely (7)
I believe the answer is:
rotates
'turns' is the definition.
(rotating is a kind of turning)
'to stare rudely' is the wordplay.
'rudely' is an anagram indicator.
'to'+'stare'='tostare'
'tostare' anagrammed gives 'ROTATES'.
(Other definitions for rotates that I've seen before include "Goes round" , "Spins round" , "revolves" , "Turns around an axis" , "Turns round" .)