One's call for help delayed in quarantines (8)
I believe the answer is:
isolates
'quarantines' is the definition.
(quarantine is a type of isolation)
'one's call for help delayed in' is the wordplay.
'one' becomes 'I' (Roman numeral).
'call for help' becomes 'sos' (I've seen this before).
'delayed' becomes 'late' (I've seen this before).
'in' is an insertion indicator.
'sos' going around 'late' is 'solates'.
'i'+'solates'='ISOLATES'
(Other definitions for isolates that I've seen before include "Sets apart from others" , "Oils seat (anag.)" , "Places apart or alone" , "Keeps apart from others" .)