WordNet (r) 3.0 (2006):

catacorner
    adj 1: slanted across a polygon on a diagonal line; "set off in
           a catty-corner direction across the vacant lot" [syn:
           catacorner, cata-cornered, catercorner, cater-
           cornered, catty-corner, catty-cornered, kitty-
           corner, kitty-cornered]