Adjusted hours to secure new career (6)
I believe the answer is:
onrush
'career' is the definition.
(I've seen this before)
'adjusted hours to secure new' is the wordplay.
'adjusted' indicates an anagram.
'to secure' means one lot of letters goes inside another.
'new' becomes 'n'.
'hours' with letters rearranged gives 'orush'.
'orush' enclosing 'n' is 'ONRUSH'.
(Other definitions for onrush that I've seen before include "Forward dash" , "Career" , "sudden swoop" , "Attack" , "Forceful forward flow" .)