Offer to get the length of a new chum (10)
I believe the answer is:
tenderfoot
'length of a new chum' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'offer to get the' is the wordplay.
'offer' becomes 'tender' (tender can mean to offer something).
'to get' becomes 'foo' (I can't explain this - if you can you should believe this answer much more).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'tender'+'foo'+'t'='TENDERFOOT'
Can you help me to learn more?
(Other definitions for tenderfoot that I've seen before include "Greenhorn" , "Raw recruit" , "Rookie" , "one still finding her bearings" , "Newcomer, novice" .)