Second tea or coffee (5)
I believe the answer is:
mocha
'coffee' is the definition.
(type of coffee drink)
'second tea' is the wordplay.
'second' becomes 'mo' (both are short periods of time).
'tea' becomes 'cha' (cha is a type of tea).
'mo'+'cha'='MOCHA'
'or' acts as a link.
(Other definitions for mocha that I've seen before include "Fine quality coffee" , "Kind of coffee" , "Kid" , "Arabian coffee" , "Coffee drink" .)