Dan's silly to get Eva in a state (6)
I believe the answer is:
nevada
'a state' is the definition.
(Nevada is an example)
'dan's silly to get eva' is the wordplay.
'silly' is an anagram indicator.
'to get' means one lot of letters goes inside another.
'dan' is an anagram of 'nda'.
'nda' enclosing 'eva' is 'NEVADA'.
'in' acts as a link.
(Other definitions for nevada that I've seen before include "State of western USA" , "part of US" , "Curiously, Dan and Eva are in the US" , "See 14" , "South-west US state" .)