Twi-weekly

The result of this liberty was that a number of weekly or twi-weekly news-sheets were soon started, which, though they were small and at first but poorly furnished with news, laid the foundation of our present-day newspaper press, wielding a power that makes the world one vast judgment-hall, and to a large extent the initiative and referendum of all measures for the public good and the advancement of civilisation.

Source: wiktionary

As a consequence of the opening of the Simplon tunnel in May, Consul J. A. Smith, of Leghorn, reports that a twi-weekly "train de luxe" is to be placed in service over the new route for passengers between England and Italy via Calais, Paris, Lausanne, and Milan.

Source: wiktionary

However, with more newspaper circulation under their direct control than the total of all 10,000 weekly, semi-weekly, and twi-weekly papers in cities under 50,000 people— with network programs on radio — and with the largest propaganda program in the nation outside government ... it has not been difficult for labor's professional officials to use the farmer as a vehicle for the advancement of their own cause.

Source: wiktionary

[…] was provided and used during all the years the mail stagecoach made its twi-weekly trips between Plymouth and Boston, thus inaugurating the first "rural delivery" which continued until the railroad succeeded the coach.

Source: wiktionary