Enthusiastic traveller initially following meanders of Blue Nile (9)
I believe the answer is:
ebullient
'enthusiastic' is the definition.
(I've seen this before)
'traveller initially following meanders of blue nile' is the wordplay.
'initially' suggests taking the first letters.
'following' is a charade indicator (letters next to each other).
'meanders of' is an anagram indicator (I've seen 'meandering' mean this).
The first letter of 'traveller' is 't'.
'blue'+'nile'='bluenile'
'bluenile' with letters rearranged gives 'ebullien'.
't' after 'ebullien' is 'EBULLIENT'.
(Other definitions for ebullient that I've seen before include "Cheerful, full of energy" , "Bouncing with enthusiasm" , "cock- a-hoop" , "Jolly" , "Bubbling with enthusiasm" .)