Craving strong drink for a number of years (7)
I believe the answer is:
lustrum
'a number of years' is the definition.
'lustrum' can be an answer for 'years' (I have seen 'several years' mean 'lustrum' so perhaps 'years' could also mean 'lustrum'). I am unsure of the 'a number of' bit.
'craving strong drink' is the wordplay.
'craving' becomes 'lust' (I can't explain this - if you can you should believe this answer much more).
'strong drink' becomes 'rum' (rum is a kind of strong drink).
'lust'+'rum'='LUSTRUM'
'for' is the link.
Can you help me to learn more?
(Other definitions for lustrum that I've seen before include "Period of 20 ac years" , "several years" , "Period of five years" , "Five-year period" .)