Dream big (6)
I believe the answer is:
aspire
'dream big' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aspire that I've seen before include "Yearn, dream (towards)" , "Persia (anag.)" , "Direct one's hopes and ambitions" , "Aim at high things" , "Have ambition or desire for praise" .)