Every atlas, I assume, will include it (4)
I believe the answer is:
asia
'it' is the definition.
The definition suggests a singular noun which matches the answer.
'every atlas i assume will include' is the wordplay.
'ASIA' is hidden within the letters.
But, I am not sure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for asia that I've seen before include "Populous area" , "its pampered jades couldn't draw much?" , "One-third of all land" , "Stretch of land" , "Tigers found here" .)