Waterproof (6)
(Other definitions for anorak that I've seen before include "good on most figures?" , "Garment (worn by boring obsessive?)" , "Zipped jacket with hood attached" , "Mikado's son (G&S)" , "Boringly obsessive person" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">waterproof</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that waterproof can be written as raincoat)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for raincoat that I've seen before include "protection against the elements" , "Catriona (anag.)" , "which should keep water out" , "Waterproof outer garment" , "Outer garment for Croatian" .)