Case that would be haunting under English

• The case (in some inflected languages) used when the referent of the noun is being addressed

WordNet Word definitions in WordNet
adj. relating to a case used in some languages; "vocative verb endings"

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Vocative \Voc"a*tive\, n. [L. vocativus (sc. casus): cf. F. vocatif.] (Gram.) The vocative case.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
early 15c., "showing the person or thing spoken to," from Middle French vocatif , from Latin vocativus (casus) "(case of) calling," from vocatus , past participle of vocare "to call" (see voice (n.)). The Latin is a translation of Greek kletike ptosis , ...

Wiktionary Word definitions in Wiktionary
a. 1 Of or pertaining to calling; used in calling or vocation. 2 (context grammar English) Used in address; appellative; — said of that case or form of the noun, pronoun, or adjective, in which a person or thing is addressed; as, ''Domine'', O Lord. n. ...