Yankee at home finds sleeveless jacket (6)
I believe the answer is:
jerkin
'sleeveless jacket' is the definition.
(I've seen this before)
'yankee at home' is the wordplay.
'yankee' becomes 'jerk' (I can't justify this - if you can you should believe this answer much more).
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
'jerk'+'in'='JERKIN'
'finds' is the link.
(Other definitions for jerkin that I've seen before include "Sleveless jacket" , "sleeveless garment" , "Tight, sleeveless, collarless jacket" , "Short coat" , "Type of coat or jacket" .)