"Adios, ___!"
(Other definitions for amigo that I've seen before include "buddy abroad?" , "Foreign ally" , "Friend in Spanish-speaking area" , "Quixote's friend" , "Friend from Spain?" .)
'adios' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for bye that I've seen before include "I'm off" , "Cheerio" , "Cricketing extra" , "(Informal) valediction" , "Run scored in cricket from a ball that passes batman" .)
(Other definitions for tata that I've seen before include "See you" , "cheerio!" , "So long!" .)