ETYM French, from Latin obliquus; ob (see Ob-) + liquis oblique; cf. licinus bent upward.
Slanting or inclined in direction or course or position--neither parallel nor perpendicular nor right-angular.
Describing a style of text created by slanting a roman font to simulate italics when a true italic font isn’t available on the computer or printer. See also font, italic, roman.
Slanting; indirect; underhand.

At a 45 degree angle

1. Something (as a line) that is oblique
2. Any grammatical case other than the nominative; SYN. oblique case.