Definition of "discriminator"

A person who discriminates, as:

1. A person who differentiates things or concepts.  quotations  examples

   Quotations

   • Generally, we may say, that Mr. Smith is a very accomplished etymological scholar, a very keen discriminator, and that his illustrative examples are selected with great industry, and from a wide field of English literature […]

     1871, The British Quarterly Review, volume 54, page 279

2. A person who acts unfairly through prejudice.  examples

A test or variable, etc. that serves to distinguish between different things.  examples

(physics) Any of several electronic devices that convert some property of a signal into an amplitude whose value is proportional to the difference between the value of the input signal and that of a standard.  examples

(marketing) A feature of the seller's offering that differs from a competitor's offering and is important to the buyer in question.  examples