There are multiple origins and meanings for the name:
1. Comes from the Greek word (κάσσια) meaning - "senna (herb)"
2. Feminine form of the given name Cassus - "vain, fruitless, empty, devoid, inane".
3. Shortened form of the given name Cassandra
4. Latin, Hebrew (קסיה) meaning - "cinnamon", see the name Casia
5. See the name Kassia
In The Bible Cassia - Job`s second daughter, born after the restoration of his prosperity (Job 42:14). Cassia gens - was a patrician family at Ancient Rome.