in the least int·he·least uncommon adverb 1. to any extent at all “are you in the least interested?” Synonymsin the leasteven a little 2. in the slightest degree or in any respect “Are you at all interested? No, not at all” “was not in the least unfriendly” Synonymsat allin the leastthe least bit WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.