Draw tailless bird surrounded by river (6)
I believe the answer is:
deduce
'draw' is the definition.
(thesaurus)
'tailless bird surrounded by river' is the wordplay.
'tailless bird' becomes 'duc' (I am not sure about this - if you are sure you should believe this answer much more).
'surrounded by' means one lot of letters goes inside another.
'river' becomes 'dee' (River Dee).
'duc' put inside 'dee' is 'DEDUCE'.
Can you help me to learn more?
(Other definitions for deduce that I've seen before include "Infer like Sherlock" , "Reason out (something)" , "Draw conclusion" , "Work out" , "Arrive at conclusion through reasoning, as Sherlock Holmes did" .)