What is "tathata"

Tathātā ( Sanskrit, Pali; ; ) is variously translated as "thusness" or "suchness". It is a central concept in Mahayana Buddhism having a particular significance in Chan Buddhism as well. The synonym dharmatā is also often used.

While alive the Buddha referred to himself as the Tathāgata, which can mean either "One who has thus come" or "One who has thus gone", and interpreted correctly can be read as "One who has arrived at suchness".