Spanish lecturer's undressed in lounge (6)
I believe the answer is:
sprawl
'lounge' is the definition.
(I've seen this before)
'spanish lecturer's undressed in' is the wordplay.
'spanish' becomes 'sp'.
'lecturer' becomes 'l' (abbreviation for lecturer).
'undressed' becomes 'raw'.
'in' indicates putting letters inside.
'sp'+'l'='spl'
'spl' enclosing 'raw' is 'SPRAWL'.
(Other definitions for sprawl that I've seen before include "10 with one's limbs extended" , "Rest in ungainly fashion - urban expansion" , "Urban or industrial expansion" , "Spread out untidily" , "Lie about in loose-limbed manner" .)