Answer:

warned

Answer	Crossword Clue
WARNED	Gave a heads-up
WARNED	Put on alert
WARNED	Put on guard

WARNED	Shot off a flare
WARNED	Gave a heads-up to
WARNED	Gave advance notice
WARNED	Alerted
WARNED	Read the riot act to
WARNED	Informed.
WARNED	Alerted.
WARNED	Cautioned

WARNED	Gave notice to
WARNED	Admonished
WARNED	Put on the alert
WARNED	On notice
WARNED	"You have been ..."
WARNED	Alerted to danger

Crossword

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