- Shockingly hideous or frightful. (adjective)
- Exceptionally large; enormous: a monstrous tidal wave. (adjective)
- Deviating greatly from the norm in appearance or structure; abnormal. (adjective)
- Of or resembling a fabulous monster. (adjective)
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.