a word which depends on the context of utterance for its meaning (e.g. I, you, here).

a reactive functional rule of the form X in R , where R is a set valued range expression (see below)

From RDF Semantics ( 2004-02-10) (adj., of an expression) having a meaning which implicitly refers to the context of use. Examples from English include words like 'here', 'now', 'this'.

of or relating to or serving as an index

Peirce] Relating to or having the characteristics of an . Links: [S4B] indexical.

Of, pertaining to, or like, an index; having the form of an index.