participant role 

A term used in LINGUISTICS, especially in PRAGMATICS, to refer to the FUNCTIONS which can be ascribed to people taking part in a linguistic interaction. Typical roles are speaker and ADDRESSEE, but several other roles can be recognized, such as the recipient (as opposed to the target) of a message, or the message’s source (as opposed to its speaker).

The term is also sometimes used in GRAMMAR, as an alternative to CASE, to refer to the SEMANTIC functions attached to CLAUSE ELEMENTS, such as AGENT, RECIPIENT and AFFECTED.