All the best English port taken by revolutionary (7)
I believe the answer is:
cheerio
'all the best english port taken by revolutionary' is the definition.
I can't judge whether this defines the answer.
'english port taken by revolutionary' is the wordplay.
'english' becomes 'e' (abbreviation).
'port' becomes 'rio' (I've seen this before).
'taken by' means one lot of letters go next to another.
'revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'e'+'rio'='erio'
'erio' put after 'che' is 'CHEERIO'.
Can you help me to learn more?
(Other definitions for cheerio that I've seen before include "Ta-ta" , "Bye" , "Bye-bye" , "Say this before drinking" , "Informal goodbye, sounds blithe" .)