deixis
noun
deix·is ˈdīk-sis 
also ˈdāk-
plural deixes ˈdīk-ˌsēz
also ˈdāk-
: the pointing or specifying function of some words (such as definite articles and demonstrative pronouns) whose denotation changes from one discourse to another
Word History
Etymology
Greek, literally, display, from deiknynai to show — more at diction
First Known Use
1946, in the meaning defined above