No tax? One working gives applause (7)
I believe the answer is:
ovation
'applause' is the definition.
(I've seen this before)
'no tax? one working' is the wordplay.
'no' becomes 'o' (O resembles 0).
'tax?' becomes 'VAT' (UK Value Added Tax).
'one' becomes 'I' (Roman numeral).
'working' becomes 'on' (on can mean working or activated).
'o'+'vat'+'i'+'on'='OVATION'
'gives' acts as a link.
(Other definitions for ovation that I've seen before include "Applause from an audience" , "Stormy applause" , "Enthusiastic applause, often standing" , "Great outburst of applause" , "Wild applause" .)