Answer:

detector

Answer	Crossword Clue
DETECTOR	Lie ... (polygraph)
DETECTOR	Airport security device
DETECTOR	Mine .. (soldier's tool)

DETECTOR	Radio tube.
DETECTOR	Radio device.
DETECTOR	Antimine device.
DETECTOR	Lie ...
DETECTOR	Radar, e.g.
DETECTOR	Lie or smoke follower
DETECTOR	Smoke ...
DETECTOR	Word after motion or smoke

DETECTOR	Geiger counter, e.g.
DETECTOR	Word after motion or lie

Crossword

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