Definition of "twice"
twice
adverb
not comparable
Quotations
He could not be induced to remain permanently at Mohair because Miss Trevor was at Asquith, but he appropriated a Hempstead cart from the Mohair stables and made the trip sometimes twice in a day.
1897 December (indicated as 1898), Winston Churchill, chapter V, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd.
(usually with "as", of a specified quality) Doubled in quantity, intensity, or degree.
Quotations
Thus it appears that if the machine is turning twice as slow as before, there is more than twice the former quantity in the rising buckets; and more will be raised in a minute by the same expenditure of power.
1826, John Nicholson, The Operative Mechanic, and British Machinist: Being a Practical Display of the Manufactories and Mechanical Arts of the United Kingdom, volume 1, H.C. Carey & I. Lea, page 78