Answer:

oos

Answer	Crossword Clue
OOS	Extinct birds of Hawaii
OOS	Hawaiian birds
OOS	Toodle-... (farewells)

OOS	Roulette bets
OOS	Hawaiian birds.
OOS	Yellow Hawaiian birds.
OOS	Hawaiian honey-eaters.
OOS	Goose eggs on the scoreboard.
OOS	Extinct honey eaters
OOS	Extinct Hawaiian birds
OOS	Agents like Bond

OOS	Agents like James Bond
OOS	Agents like Bond?

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.