Answer:

SWEATIT

Answer	Crossword Clue
SWEATIT	Worry
SWEATIT	Fret
SWEATIT	Be concerned

SWEATIT	"Don't ...!" ("Stay cool!")
SWEATIT	Worry, slangily
SWEATIT	"Don't ...!" ("Chill!")
SWEATIT	Fail to chill
SWEATIT	Be on tenterhooks
SWEATIT	Be apprehensive
SWEATIT	Worry, informally
SWEATIT	Worry too much

Crossword

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