Tailless bird sheltering in river (5)
I believe the answer is:
rhine
'river' is the definition.
(Rhine River is an example)
'tailless bird sheltering in' is the wordplay.
'tailless bird' becomes 'rhe' (I can't explain this - if you can you should believe this answer much more).
'sheltering' indicates putting letters inside.
'rhe' placed around 'in' is 'RHINE'.
Can you help me to learn more?
(Other definitions for rhine that I've seen before include "fed by 8 [RHUR]" , "River flowing from Switzerland, through Germany, to the North Sea" , "River, rising in Switzerland and flowing into the North Sea" , "valley" , "Major European river" .)