Oxygen tank is not finished going in reception (7)
I believe the answer is:
ovation
'reception' is the definition.
(I have seen 'Enthusiastic reception' mean 'ovation' so perhaps 'reception' could also mean 'ovation')
'oxygen tank is not finished going' is the wordplay.
'oxygen' becomes 'o' (atomic symbol for oxygen).
'tank' becomes 'vat' (I've seen this before).
'not finished' means to remove the last letter.
'going' becomes 'on' (both can mean functioning or activated).
'is' with its final letter taken away is 'i'.
'o'+'vat'+'i'+'on'='OVATION'
'in' acts as a link.
(Other definitions for ovation that I've seen before include "Enthuiastic applause, often standing" , "Stormy applause" , "One's often standing" , "Sustained applause (may be standing)" , "Enthusiastic applause, may be given standing" .)