Casia is of Latin origin and means "pure." It is a variant spelling of Cassia, which was originally a plant name derived from the Arabic word 'kassiyā', meaning cinnamon bark. The name Casia gained popularity in the United States during the late 20th century, perhaps influenced by the character Cassandra "Cassie" Styles from the popular television series "Beverly Hills, 90210." It is often used as a feminine given name but can also be used for males.
"The name Casia experienced a peak in popularity between 1988 and 2008, with notable spikes in 1999 (14 births) and 2008 (17 births). However, it has been less common since then, with only 6 or fewer births per year from 2010 onwards. Overall, there have been 231 recorded births with the name Casia since 1982."