This is existing in the agreement I typed (6)
I believe the answer is:
entity
'this is existing' is the definition.
The definition suggests a singular noun which matches the answer.
'in the agreement i typed' is the wordplay.
'in' indicates a hidden word.
'ENTITY' is hidden within 'the agreement i typed'.
Can you help me to learn more?
(Other definitions for entity that I've seen before include "Something with independent existence" , "It exists as a separate thing" , "Something existing in its own right" , "Individual being" , "Anything that exists" .)