For model: cheers! (6)
I believe the answer is:
prosit
'cheers' is the definition.
(German word used when raising a toast)
'for model' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'model' becomes 'sit' (e.g. for a painting).
'pro'+'sit'='PROSIT'
(Other definitions for prosit that I've seen before include "I sport during German toast to your health" , "(German for) cheers!" , "good health is the answer" , "... [good-health]" , "Happy days, perhaps" .)