Tango in a bit, you understand — now resting (2,5)
I believe the answer is:
at peace
'now resting' is the definition.
I can't judge whether this defines the answer.
'tango in a bit you understand' is the wordplay.
'tango in' becomes 'at' (I can't explain this - if you can you should give a lot more credence to this answer).
'a bit' becomes 'piece' ('piece' can be a synonym of 'bit').
'you understand' shows a homophone (sound like) (as someone hearing the word might understand it).
'piece' sounds like 'peace'.
'at'+'peace'='AT PEACE'
(Other definitions for at peace that I've seen before include "Resting serenely" , "Dead?" , "pushing up the daisies" , "In a state of serenity" , "calm" .)