Nuns stress terribly crossing Italy (7)
I believe the answer is:
sisters
'nuns' is the definition.
(I've seen this before)
'stress terribly crossing italy' is the wordplay.
'terribly' is an anagram indicator.
'crossing' means one lot of letters goes inside another.
'italy' becomes 'i'.
'stress' with letters rearranged gives 'ssters'.
'ssters' going around 'i' is 'SISTERS'.
(Other definitions for sisters that I've seen before include "Patient attention required from such" , "Resists (anag)" , "Nuns' titles" , "Resists for relatives" , "Nuns - nurses - siblings" .)