1. A name sometimes given to the upper new red sandstone.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• treas,
• trais,
• tryas,
• trails,
• trios,
• rrias,
• 6rias,
• 5rias,
• teias,
• tdias,
• tfias,
• ttias,
• t5ias,
• t4ias,
• triaa,
• trisas,
• triasz,
• Tria3,
• trius,
• Triease