A service sent up for tea (5)
I believe the answer is:
assam
'for tea' is the definition.
(I've seen this before)
'a service sent up' is the wordplay.
'service' becomes 'mass' (kind of church service).
'sent up' shows that the letters should be reversed in order.
'mass' back-to-front is 'ssam'.
'a'+'ssam'='ASSAM'
(Other definitions for assam that I've seen before include "Indian tea growing area" , "India tea-producing state" , "I'll provide lots of tea" , "Tea-producing Indian state" , "Tea-growing state in north-east India" .)