Cassi, derived from the Latin name Cassandra, means "excellent" or "prophesying". It is of Greek origin and was popularized by Shakespeare's play "Troilus and Cressida", where Cassandra was a prophetess. The name Cassi reached its peak popularity in the United States during the 1970s but remains a unique choice today.
"Cassi's popularity as a baby name peaked around the late 1980s to early 1990s, with over 100 births per year between 1982 and 1991, reaching its zenith in 1982 with 126 births. However, it has since declined significantly, with fewer than 25 births recorded annually from 2004 onwards."