that was probably the trickiest one! the definition is “herds”, and you take the tail (last letter) of “waterproof”, which is F, then find a synonym for hair- in this case its LOCKS
Nice one! One nitpick though: For 3D, I think since "unfinished" usually indicates the final letter is missing, something like "halfway through" might have been a bit fairer? (The current clue is not inaccurate per se, just a bit unconventional.)