Answer: haveatit

AnswerCrossword Clue
HAVEATIT

Begin with enthusiasm

HAVEATIT

"Dig in!"

HAVEATIT

Do battle

HAVEATIT
Get down to work, with gusto
HAVEATIT
Get started vigorously
HAVEATITMake the fur fly
HAVEATITDig in
HAVEATITAttack
HAVEATITWork with enthusiasm
HAVEATITGo mano a mano
HAVEATIT"You try!"
HAVEATITCome to blows