A science graduate working hard, ultimately, to escape (7)
I believe the answer is:
abscond
'escape' is the definition.
(I've seen this before)
'a science graduate working hard ultimately' is the wordplay.
'science graduate' becomes 'bsc' (I can't explain this - if you can you should believe this answer much more).
'working' becomes 'on'.
'ultimately' says to take the final letters.
The final letter of 'hard' is 'd'.
'a'+'bsc'+'on'+'d'='ABSCOND'
'to' is the link.
Can you help me to learn more?
(Other definitions for abscond that I've seen before include "Go away secretly after wrongdoing" , "scarper" , "cut and run" , "Make off (with the money?)" , "Run away from a legal process" .)