Semantic role

A semantic role is the role played by a participant in a situation.

Examples
In The boy cut the string with a knife, the boy has the semantic role agent, the string has the role patient, and a knife has the role instrument.

Comments
This term is not very widely used in the theoretical literature, but it is the most neutral term, being maximally transparent (not incorporating confusing components like "thematic", "case", etc.) (e.g. Quirk et al. 1985:740ff.)

Subtypes

 * agent
 * patient
 * experiencer
 * stimulus
 * theme
 * recipient
 * location
 * goal
 * source

Synonyms

 * thematic relation
 * thematic role
 * Θ-role (Theta role)
 * deep case, case role, case relation
 * semantic function (Simon Dik's Functional Grammar)
 * kāraka (Panini)

Reference

 * Quirk, Randolph & Sidney Greenbaum & Geoffrey Leech & Jan Svartvik. 1985. A Comprehensive Grammar of the English Language. Longman, Harcourt.

Other languages

 * German semantische Rolle
 * Swedish semantisk roll