The story
- Latinconceptus
- Middle Frenchconcept
- Englishconcept
- Proto-Indo-European*lewh₁-
- Proto-Indo-European*lewHs-
- Proto-Germanic*leusaną
- Proto-Germanic*lausaz
- Englishconceptless
- English todayconceptlessness
From conceptless + -ness.
Etymology from Wiktionary, CC BY-SA 4.0.