It always amazes me how close the versions of English are in the USA and the UK, but how we still manage to confuse each other. The two-volume Oxford gives us "a small, secluded or secret room; a water-closet". The Prime Minister is closeted with the King means "in a private meeting with". Where's Gran? She's in the closet, means Gran has gone to the bathroom, American style, i.e, the toilet.
Don't say "closet" in England. It's a wardrobe. In Ireland, you put your underclothing in the "press" (chest of drawers). Don't ask.