Desert watering hole near gambling city is unfinished (6)
I believe the answer is:
barren
'desert watering hole' is the definition.
'barren' can be an answer for 'desert' (thesaurus). I am unsure of the 'watering hole' bit.
'near gambling city is unfinished' is the wordplay.
'near gambling' becomes 'bar' (I can't explain this - if you can you should give a lot more credence to this answer).
'city' becomes 'reno' (city in Nevada).
'is unfinished' means to remove the last letter.
'reno' with its final letter removed is 'ren'.
'bar'+'ren'='BARREN'
Can you help me to learn more?
(Other definitions for barren that I've seen before include "Sterile" , "Not producing vegetation or offspring" , "Unable to reproduce, infertile" , "Arid, infertile" , "Dull" .)