Go get soil so he may study it (9)
I believe the answer is:
geologist
'he may study it' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'go get soil' is the wordplay.
'go get soil' can be anagrammed to 'GEOLOGIST'.
But, I am not sure how the anagram is indicated.
'so' is the link.
Can you help me to learn more?
(Other definitions for geologist that I've seen before include "One studying the earth's crust" , "Specialist in the physical history of the earth" , "One studying the earth's structure" , "Specialist in the earth's history recorded in rocks" , "One studying rocks" .)