The name Tanis is a girl's name of Spanish origin. Tanis and is often added to lists like Gothic Baby Names and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
This obscure name found in Sinclair Lewis's 1923 novel Babbitt is a bit hipper than most other is-ending names like Janis and Doris. It is a variation of Tanith, who is a Phoenician serpent goddess.