from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Requiring the full application of one's abilities, attention, or resources.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective requiring full use of one's abilities or resources.
  • adjective disposed to or engaged in defiance of established authority.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • verb Present participle of challenge.
  • adjective Difficult, hard to do.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective stimulating interest or thought
  • adjective disturbingly provocative
  • adjective requiring full use of your abilities or resources


Sorry, no etymologies found.


    Sorry, no example sentences found.


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