Tiarnan is a person with a deformity in the male genitalia. It is extremely small and often shrinks into the abdomen, which can cause random and violent twitches of confusion, rage, and shame. They also have problems associated with mental retardation including drooling, licking of windows, and public masturbation habits. Often a slang word for a "retard"
by guttedmateee August 01, 2011