Answer: giddap

AnswerCrossword Clue
GIDDAPGet up!
GIDDAPWord urging Dobbin.
GIDDAPBuggy driver's command.
GIDDAPCommand to dobbin.
GIDDAPCommand to a horse
GIDDAPOpposite of "Whoa!"
GIDDAPCommand to Dobbin
GIDDAPOpposite of "whoa!" (Var.)
GIDDAPOpposite of "whoa!"
giddapused to tell a horse to go faster, also GIDDYAP, GIDDYUP
giddap(used as a command to a horse to speed up)
giddapa command (as to a horse) to go ahead or go faster