Tigris (TY-griss) is a name of Latin origin meaning "tiger," and it is used as the species name of the tiger family, Panthera Tigris. It is the name of the Tigris River that runs through Iraq and Turkey, and it connects with the Euphrates River. Legend has it that Saint Patrick had a sister named Tigris, and she is listed as a Catholic saint in her own right. She had at least five children, and it is said that they were five boys who all became bishops - one of which may have been Saint Loman of Trim. In Thermodon and Tiigris were the two river spirits Romans knew as Flumina, but they represented every river. In the movie Gladiator, the main character fights "the undefeated" Tigris of Gaul, and there is a Tigris character in The Hunger Games series as well.
A tigress (TY-gress) is a female tiger. The Tigress is the name of a 1927 silent film and a 1992 German film. There are characters named Tigress in DC Comics, Kung Fu Panda, and the Tigress comics by Heroic Publishing.
Although word names are popular, Tigress (female) and Tigris (unisex) are very rare, with no government statistics. It is also worth nothing that Tiger is used as a name, mainly for boys. In 2015 Tiger was not used on girls, but was given to 28 boys, and in general since at least 1962. Tigra, a feminine name with the same meaning, was only used five times in 1988 and five times in 1991.