[fath-uh m-lis]


impossible to measure the depth of; bottomless.
impossible to understand; incomprehensible: fathomless motives.

Origin of fathomless

First recorded in 1600–10; fathom + -less
Related formsfath·om·less·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fathomless

Contemporary Examples of fathomless

  • Of course, no one should blame the intellectuals for not being able to grasp our fathomless economic mess.

    The Daily Beast logo
    The Intellectual Crash of 2009

    Lee Siegel

    March 25, 2009

Historical Examples of fathomless

  • The fathomless eyes, full of gloom and of an immense despair, did not close.

    Doctor Pascal

    Emile Zola

  • She had probed its depth and found it fathomless––fathomless in its devotion to herself.

  • There is a fathomless look in his eyes and he is cold and unresponsive.

    Mary Louise in the Country

    L. Frank Baum (AKA Edith Van Dyne)

  • It is the home of the Archean granite, and its basins are of a fathomless dust.

    Whispering Smith

    Frank H. Spearman

  • All the cone trembled as if it was about to plunge into a fathomless gulf.

British Dictionary definitions for fathomless



another word for unfathomable
Derived Formsfathomlessly, adverbfathomlessness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fathomless

1630s, literal; 1640s, figurative; from fathom + -less.

Online Etymology Dictionary, © 2010 Douglas Harper