Part of speech: Noun
a downward slope or bend
The word "declivity" comes from Proto-Indo-European *ḱley-. It started in Proto-Indo-European *ḱleywo-. Then it appeared in Latin declivitatem. Later, people used it in French déclivité.
lean – A related word in the same word family.
Each language in this chain added phonetic changes that transformed the original sound.