thatness

As a noun thatness

is the quality or characteristic of being that (something referred to).

As an adjective undefined is

lacking a definition or value.

As nouns the difference between phatness and thatness

is that phatness is fullness, richness, body while thatness is the quality or characteristic of being that (something referred to).

As nouns the difference between whatness and thatness

is that whatness is essence; quiddity while thatness is the quality or characteristic of being that (something referred to).

As nouns the difference between taxonomy and thatness

is that taxonomy is the science or the technique used to make a classification while thatness is the quality or characteristic of being that (something referred to).

Thisness is a related term of thatness.

As nouns the difference between thisness and thatness

is that thisness is the qualities]], [[property|properties or characteristics of a thing which make it a particular thing while thatness is the quality or characteristic of being that (something referred to).