The story
- Latin · derived fromsollemnitās
- Old French · derived fromsolemnite
- Middle English · derived fromsolemnity“observance of formality and ceremony”
- English todaysolemnity
From solemn + -ity, from Middle English solemnity (“observance of formality and ceremony”), frequently in the phrases in solemnity, with solemnity, which from Old French solemnite, from Latin sollemnitās, from sollemnis. (Compare solemn.)
Etymology from Wiktionary, CC BY-SA 4.0.