Observes that ices are absent (7)
I believe the answer is:
notices
'observes that ices are absent' is the definition.
'notices' can be an answer for 'observes' (I've seen this before). I'm not sure about the rest of the definition.
'observes that ices' is the wordplay.
'observes' becomes 'not' (I am not sure about this - if you are sure you should believe this answer much more).
'that ices' becomes 'ices'.
'not'+'ices'='NOTICES'
Can you help me to learn more?
(Other definitions for notices that I've seen before include "Observers in section" , "Pays attention" , "Sees; adverts" , "Discovers" , "reviews" .)