pronunc at demonstrate +ə(r) noun
( -s )
Etymology: French or Latin; French démonstrateur, from Latin demonstrator, from demonstratus + -or
: one that demonstrates or makes a demonstration: as
a. : a teacher or teacher's assistant in a professional school or a science department who demonstrates the principles and theories studied (as by means of experiments, dissections, physical and chemical preparations)
b. : one that demonstrates an article or product to a prospective buyer ; also : an article or product (as an automobile or vacuum cleaner) used in a demonstration
c. : one engaged in a public demonstration
demonstrators protesting the pact