楣 by itself means 'lintel' (the beam over a door). In
倒楣 (dǎoméi — to be unlucky), the character is combined with
倒 (to fall/topple). Imagine the beam above the door collapsing — that's bad luck! Note:
楣 is sometimes written
霉 (mold) in
倒霉, the more common variant.
