A small toothed whale (Delphinapterus leucas), chiefly of northern waters, that is white when full-grown. Also called beluga, sea canary.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "white whale" in a sentence
"Always the District, it was Tazza’s white whale and he would have it."