European mountain range (3,4)
'european mountain range' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for alps that I've seen before include "Slap about in mountains" , "Mont Blanc is therein" , "European mountain chain" , "Pals seen in mountains" , "With pals in great mountains" .)
(Other definitions for the alps that I've seen before include "heights" , "natural barrier" , "Range" .)