The story
- Latin · derived fromtranquillitas
- Old French · derived fromtranquillite
- Middle English · inherited fromtranquillite
- English todaytranquillity
From tranquil + -ity, from Middle English tranquillite, from Old French tranquillite, tranquilité, from Latin tranquillitas.
Etymology from Wiktionary, CC BY-SA 4.0.