Answer: trigger

AnswerCrossword Clue
TRIGGERButtermilk's companion
triggerdevice pressed to release a spring
triggerto set in action
triggerto make trim, smart, etc. (often fol. by up or out)
triggerin good physical condition; sound; well
triggerprojecting tongue pressed to fire a gun
triggerquick to act or respond; impetuous; alert
triggerto cause (a reaction, process, etc.)
triggerneat, trim, smart, or spruce
TRIGGERCause
TRIGGERHe ran under Rogers
TRIGGERRoy Rogers' horse
TRIGGERFinger lever
TRIGGERRoy Rogers's horse
TRIGGERRoy Rogers's steed
TRIGGERRoy Rogers's palomino
TRIGGERFamous movie horse.
TRIGGERRoy Rogers' horse.
TRIGGERNoted movie equine.
TRIGGERRoy Rogers' co-star.
TRIGGER"The smartest horse in the movies"
TRIGGERActivate
TRIGGERSet off