Methuselah had to complete a course his boss thought up (7)
I believe the answer is:
ideated
'thought up' is the definition.
(I've seen this in another clue)
'methuselah had to complete a course his boss' is the wordplay.
I cannot really see how this works, but
'methuselah' could be 'i' (where the crossword setter is 'Methuselah') and 'i' is present in the answer.
'had' could be 'd' (I've seen this in other clues) and 'd' is present in the answer.
'a' is found in the answer.
'course' could be 'e' and 'e' is found within the answer.
'boss' could be 'ed' (short for editor - newspaper boss) and 'ed' is present in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?