Celebrity gambling resort, Western Nevada's foremost (6)
I believe the answer is:
renown
'celebrity' is the definition.
(synonyms)
'gambling resort western nevada's foremost' is the wordplay.
'gambling resort' becomes 'reno' (I've seen this before).
'foremost' indicates taking the first letters.
The initial letters of 'western nevada' is 'wn'.
'reno'+'wn'='RENOWN'
(Other definitions for renown that I've seen before include "Fame and eminence" , "High repute" , "Good reputation" , "Fame and distinction" , "Plane's maximum width" .)