Charge one guinea to visit an island (7)
I believe the answer is:
arraign
'charge' is the definition.
(I know this)
'one guinea to visit an island' is the wordplay.
'one' becomes 'I' (Roman numeral).
'guinea' becomes 'g' (this might be a standard abbreviation which I don't know about).
'to visit' indicates putting letters inside.
'an island' becomes 'arran' (Isle of Arran in Scotland).
'i'+'g'='ig'
'ig' inserted into 'arran' is 'ARRAIGN'.
Can you help me to learn more?
(Other definitions for arraign that I've seen before include "Indict, accuse" , "Accuse of a wrong" , "Summons" , "Call before court to answer criminal charge" , "Complain about" .)