Oppressed worker left during rescue (5)
I believe the answer is:
slave
'oppressed worker' is the definition.
'slave' can be an answer for 'worker' (slave is a kind of worker). I am unsure of the 'oppressed' bit.
'left during rescue' is the wordplay.
'left' becomes 'l' (common abbreviation).
'during' is an insertion indicator.
'rescue' becomes 'save' (saving is a kind of rescuing).
'l' put within 'save' is 'SLAVE'.
Can you help me to learn more?
(Other definitions for slave that I've seen before include "Person who is the property of another" , "Person in thraldom" , "Unpaid worker" , "Forced labourer" , "One bound to serve" .)