Oblique

The term oblique is used in two subtly but crucially different senses:
 * a clausal argument or adjunct that is coded in some special way (by means of an adposition or a semantic case), contrasting with core arguments, which are generally coded without case-marking or with grammatical case-marking; see oblique (a grammatical relation);
 * non-nominative case; see oblique case.

Sometimes one also finds a mixture of these two uses, as when oblique case refers to cases other than those that mark core arguments (nominative and accusative, ergative and absolutive, perhaps also dative).