Ruddy cut having necked last of molly and grass (3)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

RE [d] (ruddy) without the last letter (cut), containing the last letter of [moll] Y . (It seems molly is street slang for MDMA or associated illegal drugs, but the dictionaries may not have caught up with that yet.) Rye = a type of coarse grass.