Crossword Clue:

to warn beforehand

AnswerCrossword Clue
FOREStart to warn
MONITORIALServing to warn.
SEAMARKSBeacons to warn mariners.
GALEReason to warn boaters
ORELSEWords to warn you
BELLDevice to warn mice of cats.
KNOCKDOWNPITCHHurler's strategy to warn the hitter
THEBOGEYMANWhat a parent might warn a child to watch out for