Too grand to follow apprentice's lead (2,4)
I believe the answer is:
as well
'too' is the definition.
(synonyms)
'grand to follow apprentice's lead' is the wordplay.
'grand' becomes 'swell' (I've seen this before).
'to follow' means one lot of letters go next to another (some letters go after or follow others).
'lead' says to take the initial letters.
The initial letter of 'apprentices' is 'a'.
'swell' put after 'a' is 'AS WELL'.
(Other definitions for as well that I've seen before include "Also, additionally" , "To boot" , "Appropriate" , "Also, in addition" , "with equal effect" .)