Second week inside the bubble (6)
I believe the answer is:
seethe
'bubble' is the definition.
(thesaurus)
'second week inside the' is the wordplay.
'second' becomes 's' (common abbreviation).
'inside' says to take the centre.
The middle of 'week' is 'ee'.
's'+'ee'+'the'='SEETHE'
(Other definitions for seethe that I've seen before include "Bubble away" , "Bubble gently like boiling water" , "Boil; be intensely angry" , "get very agitated" , "foam at the mouth" .)