Former name: optical density, τ. physics a measure of the extent to which a substance transmits light or other electromagnetic radiation, equal to the logarithm to base ten of the reciprocal of the transmittance
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
Remember new words for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.