One missing a worker made to go inside (8)
I believe the answer is:
absentee
'one missing' is the definition.
(someone who is absent)
'a worker made to go inside' is the wordplay.
'worker' becomes 'bee' (a worker bee).
'made' becomes 'sent' (I can't justify this - if you can you should give a lot more credence to this answer).
'to go inside' means one lot of letters goes inside another.
'bee' placed around 'sent' is 'bsentee'.
'a'+'bsentee'='ABSENTEE'
Can you help me to learn more?
(Other definitions for absentee that I've seen before include "Deserter - truant b" , "Someone not present" , "skiver" , "one's failed to show up" , "One failing to attend" .)