Eager to know about the Orient (4)
I believe the answer is:
keen
'eager' is the definition.
(thesaurus)
'know about the orient' is the wordplay.
'know' becomes 'ken' (I've seen this in other clues).
'about' indicates putting letters inside.
'the orient' becomes 'e'.
'ken' going around 'e' is 'KEEN'.
'to' is the link.
(Other definitions for keen that I've seen before include "Sharp -- express grief" , "Enthusiastic or sharp" , "Sharp - avid" , "Fervent" , "Piercing" .)