The date of Tarcil's birth appears only in The History of Middle-earth volume XII, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.
Tarcil's name derives from an Elvish term that could be applied to any of the Dúnedain. It derives from tar 'high' and khil 'Man' (which had its origin in Hildor, 'the Followers', a name for all Men). The Orcs used a degraded form of this same word when they referred insultingly to the Men of Gondor as tarks.