Also found in: Thesaurus.
1. Impossible to comprehend or grasp fully: inconceivable folly; an inconceivable disaster.
2. So unlikely or surprising as to have been thought impossible; unbelievable: an inconceivable victory against all odds.
in′con·ceiv′a·bil′i·ty, in′con·ceiv′a·ble·ness n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.