Escaped convict has periodical yen to drink whiskey (8)

I believe the answer is:

magwitch

I'm a little stuck... Click here to teach me more about this clue!

'escaped convict' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'periodical yen to drink whiskey' is the wordplay.
'periodical' becomes 'mag' (abbreviation for magazine).
'yen' becomes 'itch' (I've seen this before).
'to drink' means one lot of letters goes inside another.
'whiskey' becomes 'W' (phonetic alphabet: alpha, bravo, charlie etc.).
'mag'+'itch'='magitch'
'magitch' enclosing 'w' is 'MAGWITCH'.

'has' acts as a link.

Can you help me to learn more?

(Other definitions for magwitch that I've seen before include "Convict in Great Expectations" , "Character in Great Expectations" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app