I can rave about the ultimate in Apple roaming (9)
I believe the answer is:
itinerant
'roaming' is the definition.
(thesaurus)
'i can rave about the ultimate in apple' is the wordplay.
'i can' becomes 'itin' (I am not sure about this - if you are sure you should believe this answer much more).
'rave' becomes 'rant' (synonyms).
'about' says to put letters next to each other.
'the ultimate in' indicates one should take the final letters (take the ultimate ie last letter).
The last letter of 'apple' is 'e'.
'rant' put after 'e' is 'erant'.
'itin'+'erant'='ITINERANT'
Can you help me to learn more?
(Other definitions for itinerant that I've seen before include "(Person) on the move" , "Wanderer" , "Nomad" , "Rambling" , "Person who moves from place to place" .)