Earnings drained after tax returns in future? (5)
I believe the answer is:
tense
'future?' is the definition.
(future tense)
'earnings drained after tax returns' is the wordplay.
'drained' means to remove the middle letters.
'after tax' becomes 'net' (as in net profits).
'returns' shows that the letters should be reversed in order.
'earnings' with its centre removed is 'es'.
'es'+'net'='esnet'
'esnet' back-to-front is 'TENSE'.
'in' is the link.
(Other definitions for tense that I've seen before include "perfect, perhaps" , "Charged" , "Strained - form of verb" , "past, say" , "show strain" .)