President on prohibition and adult art from Japan (7)
I believe the answer is:
ikebana
'art from japan' is the definition.
(Japanese flower arrangement)
'president on prohibition and adult' is the wordplay.
'president' becomes 'ike' (nickname of Dwight Eisenhower).
'on' says to put letters next to each other.
'prohibition' becomes 'ban' (synonyms).
'and' means one lot of letters go next to another.
'adult' becomes 'a' (abbreviation).
'ike'+'ban'+'a'='IKEBANA'
(Other definitions for ikebana that I've seen before include "Art of Japanese flower arrangement" , "Flower arranging; In a bake (anag.)" , "Jap. flower arranging" , "Japanese flower-arranging art" , "exhibiting array of bloomers" .)