Student of poor classes, one out of place in stream (9)
I believe the answer is:
steinbeck
'student of poor classes one' is the definition.
The definition suggests a singular noun which matches the answer.
'place in stream' is the wordplay.
'place in' becomes 'stein' (I can't justify this - if you can you should give a lot more credence to this answer).
'stream' becomes 'beck' (northern English dialect term for 'stream').
'stein'+'beck'='STEINBECK'
'out of' is the link.
Can you help me to learn more?
(Other definitions for steinbeck that I've seen before include "Of Mice and Men author" , "20th century American author" , "US writer" , "Novelist" , "John ......, author of 'The Grapes of Wrath'" .)
