Elegant American gal, room changed first (9)
I believe the answer is:
glamorous
'elegant' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I can't see?
'american gal room changed first' is the wordplay.
'american' becomes 'us' (abbreviation for United States).
'changed' is an anagram indicator.
'first' says to put letters next to each other.
'gal'+'room'='galroom'
'galroom' is an anagram of 'glamoro'.
'us' put after 'glamoro' is 'GLAMOROUS'.
Can you help me to learn more?
(Other definitions for glamorous that I've seen before include "Excitingly attractive" , "Alluringly appealing" , "Smart; glittering" , "Alluring" , "in a showy way?" .)