Answer:

arduous

Answer	Crossword Clue
ARDUOUS	Difficult
ARDUOUS	Herculean
ARDUOUS	Trying

ARDUOUS	Burdensome
ARDUOUS	Backbreaking
ARDUOUS	Tough to accomplish
ARDUOUS	Laborious.
ARDUOUS	Difficult to do.
ARDUOUS	Strenuous.
ARDUOUS	Toilsome.
ARDUOUS	Hard.

ARDUOUS	Gruelling
ARDUOUS	Demanding

Crossword

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