Troubadour Mrs let in, unwisely (8)
I believe the answer is:
minstrel
'troubadour' is the definition.
('minstrel' can be a synonym of 'troubadour')
'mrs let in unwisely' is the wordplay.
'unwisely' is an anagram indicator.
'mrs'+'let'+'in'='mrsletin'
'mrsletin' is an anagram of 'MINSTREL'.
(Other definitions for minstrel that I've seen before include "the last person to inspire a lay!" , "Jongleur" , "Old travelling musician - a boy in Irish song" , "Mediaeval entertainer" , "Singer of folk songs" .)