'Demonstrator' definitions:

Definition of 'demonstrator'

(from WordNet)
noun
A teacher or teacher's assistant who demonstrates the principles that are being taught
noun
Someone who demonstrates an article to a prospective buyer [syn: demonstrator, sales demonstrator]
noun
Someone who participates in a public display of group feeling [syn: demonstrator, protester]

Definition of 'Demonstrator'

From: GCIDE
  • Demonstrator \Dem"on*stra`tor\ (?; 277), n. [L.: cf. F. d['e]monstrateur.]
  • 1. One who demonstrates; specif. (a) one who proves anything with certainty, or establishes it by indubitable evidence. (b) one who shows how a certain device operates or a procedure is performed. [1913 Webster]
  • 2. (Anat.) A teacher of practical anatomy. [1913 Webster]
  • 3. a person who participates in a demonstration[7]. [PJC]