Into Panama sailed East African (5)
I believe the answer is:
masai
'african' is the definition.
(the Masai are an ethnic group of Kenya)
'into panama sailed east' is the wordplay.
'into' indicates a hidden word.
'MASAI' is hidden within 'panama sailed east'.
(Other definitions for masai that I've seen before include "Member of an African pastoral people" , "Africans" , "E.African pastoral people" , "Kenyan language" , "East African people" .)