Qualified teacher strikes to get retirement cover (8)
I believe the answer is:
bedsocks
'retirement cover' is the definition.
(socks worn after retiring to bed)
'qualified teacher strikes' is the wordplay.
'qualified teacher' becomes 'BEd' (someone with a Bachelor of Education degree).
'strikes' becomes 'socks' (I've seen this before).
'bed'+'socks'='BEDSOCKS'
'to get' is the link.
(Other definitions for bedsocks that I've seen before include "Night-time wear" , "Nighttime attire" , "Night attire" , "Night wear for feet" , "Night-time footwear" .)