American lover once wearing brown (5)
I believe the answer is:
texan
'american' is the definition.
(Texan is an example)
'lover once wearing brown' is the wordplay.
'lover once' becomes 'ex' (an ex-lover).
'wearing' indicates putting letters inside.
'brown' becomes 'tan' (tan is a kind of brown).
'ex' put inside 'tan' is 'TEXAN'.
(Other definitions for texan that I've seen before include "Inhabitant of Dallas?" , "Native of Dallas, say" , "Native of Houston, perhaps" , "Person from southwestern US state" , "Eg, native of Dallas" .)