Two rums originally in strong drink (6)
I believe the answer is:
bracer
'strong drink' is the definition.
(alcoholic drink which braces someone for something)
'two rums originally' is the wordplay.
'two' becomes 'brace' (brace is a kind of two).
'originally' says to take the initial letters.
The first letter of 'rums' is 'r'.
'brace'+'r'='BRACER'
'in' acts as a link.
(Other definitions for bracer that I've seen before include "Restorative drink" , "stiff drink" , "strong drink" , "Wrist guard used in archery -- shot of Dutch courage" , "Strengthening drink" .)