Certificate for travel initiated by official (8)
I believe the answer is:
diplomat
'official' is the definition.
(I know that diplomat is a type of senior government officials)
'certificate for travel initiated' is the wordplay.
'certificate' becomes 'diploma' (academic certificate).
'for' means one lot of letters go next to another.
'initiated' suggests taking the first letters.
The initial letter of 'travel' is 't'.
'diploma'+'t'='DIPLOMAT'
'by' acts as a link.
(Other definitions for diplomat that I've seen before include "Limp toad (anag.)" , "tactful one" , "Tactful person, maybe in public service" , "One deals tactfully with others" , "Our Man in Havana" .)