Answer:

goodbye

Answer	Crossword Clue
GOODBYE	Peoria farewell!
GOODBYE	Parting word
GOODBYE	So long

GOODBYE	Splitting word?
GOODBYE	Word to Mr. Chips
GOODBYE	"... Yellow Brick Road" (Elton John tune)
GOODBYE	"See you later"
GOODBYE	"Farewell!"
GOODBYE	Tosti's well-known song.
GOODBYE	The last word.
GOODBYE	Simon's "The ... Girl"

GOODBYE	"Adieu"
GOODBYE	"The Weakest Link" phrase
GOODBYE	Philip Roth title word
GOODBYE	Aloha, sometimes