measuring instrument mea·su·rin·ginstrument uncommon noun 1. instrument that shows the extent or amount or quantity or degree of something Synonymsmeasuring instrumentmeasuring systemmeasuring device Related words Broader terms instrument Narrower terms accelerometeractinometeralgometeraltazimuthaltimeteratmometeraudiometerbarometer WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.