Storm encountered on the way back - a nuisance (7)
I believe the answer is:
tempest
'storm' is the definition.
(tempest is a kind of storm)
'encountered on the way back a nuisance' is the wordplay.
'encountered' becomes 'met' ('meet' can be a synonym of 'encounter').
'on the way back' shows that the letters should be reversed in order.
'a nuisance' becomes 'pest' (I've seen this before).
'met' backwards is 'tem'.
'tem'+'pest'='TEMPEST'
(Other definitions for tempest that I've seen before include "Met pets in fierce storm" , "Violent disturbance" , "Shakesperian storm" , "A violent storm like Shakespeare's" , "terrible blow" .)