Answer:

turnsignal

Answer	Crossword Clue
TURNSIGNAL	Aid in traffic flow
TURNSIGNAL	Blinker
TURNSIGNAL	Auto blinker

TURNSIGNAL	Automobile feature
TURNSIGNAL	Smell of sour milk?
TURNSIGNAL	Flashing light
TURNSIGNAL	It creates a flashing light
TURNSIGNAL	Course-changing light
TURNSIGNAL	It involves a flashing light

Crossword

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