The story
- Anglo-Normancressaunt
- Proto-Indo-European*ḱer-
- Proto-Indo-European*ḱreh₁-sḱéti
- Latincrēscō
- Latincrēscentem
- Old Frenchcreissant
- Middle Englishcressaunt
- Englishcrescent
- English todaycrescentic
From crescent (“(growing) half moon”) + -ic. More at crescent.
Etymology from Wiktionary, CC BY-SA 4.0.