Likely a variant of Tierney, an Irish surname and given name meaning lordly or noble.
Tiereny is likely a variant of Tierney, an Irish surname and given name meaning lordly or noble. That gives the name a clear aristocratic or elevated sense, even though the modern spelling makes it feel more individualized.
It belongs to the large family of Irish names that have moved from surname to first name use. In modern use, Tiereny feels soft, contemporary, and lightly traditional. It retains the dignity of the original Irish root while adopting a more stylized spelling.
The result is rare but readable, with enough familiarity to feel approachable. Tiereny carries nobility in meaning, but the sound is gentle and modern.