Sloping letters (7)
I believe the answer is:
italics
'sloping letters' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for italics that I've seen before include "Letters slanting upward to the right" , "Typeface with letters slanting to the right" , "Sloping typeface" , "They emphasise" , "Sloping font" .)