— gin fizz (4)
(Other definitions for sloe that I've seen before include "Black fruit" , "Fruit steeped in gin to make a liqueur" , "Fruit often used for gin" , "Musical study" , "Sour blackthorn fruit" .)
(Other definitions for slope that I've seen before include "Rake; Barchester chaplain" , "Poles for gradient" , "Be inclined" , "Tilt with poles" , "bank" .)