Definition from Wiktionary, the free dictionary
thrice (not comparable)
- Unlike once and twice, thrice is somewhat dated in American and British usage, often used for a comical or intentionally archaic effect. Three times is the more standard and typical usage. On the other hand, once and twice are almost always preferred over one time and two times respectively. Thrice does however retain some currency in compounds like thrice-monthly, and it is still standard and stylistically neutral in Indian English.