Treena, of Latin origin, means "trinity". It was popular during the mid-20th century but has since become less common. The name is associated with a character from the television series "Battlestar Galactica", which may have contributed to its popularity at one point. Treena is often shortened to 'Tre'.
"After a slow start with only 5 births each in 1946 and 1948, the name Treena gained popularity throughout the late 50s to mid-70s, peaking at 64 births in 1969. However, it began declining thereafter, dropping below double digits by the early 80s and remaining low ever since."