Sense teen is upset, in a state (9)
I believe the answer is:
tennessee
'state' is the definition.
(I know that Tennessee is a state)
'sense teen is upset' is the wordplay.
'is upset' indicates anagramming the letters (I've seen 'are upset' mean this).
'sense'+'teen'='senseteen'
'senseteen' is an anagram of 'TENNESSEE'.
'in a' acts as a link.
(Other definitions for tennessee that I've seen before include "Volunteer State" , "playwright's assumed first name" , "Seen teens in this US state" , "US state, capital Nashville" , "Teen sense observed in American state" .)