Secured a routine job and set about it (8)
I believe the answer is:
anchored
'secured' is the definition.
(anchoring is a kind of securing)
'a routine job and set about it' is the wordplay.
'routine job' becomes 'chore' (I've seen this in another clue).
'and' becomes 'n' (common abbreviation for 'and').
'set' becomes 'd' (I can't explain this - if you can you should believe this answer much more).
'about it' is an insertion indicator (some letters go around or about others).
'n'+'d'='nd'
'chore' inserted into 'nd' is 'nchored'.
'a'+'nchored'='ANCHORED'
Can you help me to learn more?
(Other definitions for anchored that I've seen before include "Firmly tethered" , "Made fast, secured" , "Fixed firmly and securely" , "In immovable position" , "secure so?" .)