Spray a wild rose and look up (7)
I believe the answer is:
aerosol
'spray' is the definition.
(thesaurus)
'a wild rose and look up' is the wordplay.
'wild' is an anagram indicator.
'and' is a charade indicator (letters next to each other).
'look' becomes 'lo'.
'up' says the letters should be written backwards (in down clue: letters go upwards).
'lo' backwards is 'ol'.
'rose' is an anagram of 'eros'.
'a'+'eros'+'ol'='AEROSOL'
(Other definitions for aerosol that I've seen before include "O so real (anag.)" , "Sprayer" , "Spray producer" , "It dispenses liquid in a fine spray" , "What makes mist" .)