frightful or hideous, especially in appearance; extremely ugly.
shocking or revolting; outrageous: monstrous cruelty.
extraordinarily great; huge; immense: a monstrous building.
deviating grotesquely from the natural or normal form or type.
having the nature or appearance of a fabulous monster.


extremely; exceedingly; very.

Origin of monstrous

First recorded in 1350–1400; Middle English word from Latin word mōnstrōsus. See monster, -ous
Related formsmon·strous·ly, adverbmon·strous·ness, noun

Synonyms for monstrous

1, 2. horrible, atrocious. 3. See gigantic. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for monstrous

Contemporary Examples of monstrous

Historical Examples of monstrous

  • A non-loving Universal Thought was too monstrous a concept to entertain.

  • I do know that you did it for love of me, monstrous though it sounds to say so.

  • She thinks it monstrous because she has eyes in her head; she thinks it monstrous because it is monstrous.

    Alarms and Discursions

    G. K. Chesterton

  • They had sent this monstrous caricature of the most beautiful thing in the world.

    My Double Life

    Sarah Bernhardt

  • His design then appeared to him insane, monstrous, polluting.

British Dictionary definitions for monstrous



abnormal, hideous, or unnatural in size, character, etc
(of plants and animals) abnormal in structure
outrageous, atrocious, or shockingit is monstrous how badly he is treated
hugea monstrous fire
of, relating to, or resembling a monster
Derived Formsmonstrously, adverbmonstrousness, 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 monstrous

mid-15c., "unnatural, deviating from the natural order, hideous," from Middle French monstrueux, from Latin monstruosus "strange, unnatural, monstrous," from monstrum (see monster). Meaning "enormous" is from c.1500; that of "outrageously wrong" is from 1570s. Earlier form monstruous (late 14c., from Old French monstruous) was "very common in the 16th c." [OED].

Online Etymology Dictionary, © 2010 Douglas Harper