Biweekly comes from Latin bi- ('two, twice') + weekly, from week (Old English wicu) + -ly. The historical trail runs through bi- in Latin and wicu in Old English. Morphologically, biweekly is transparent: it draws on Latin bi- ('two, twice') + weekly, from week (Old English wicu) + -ly. Used as an adjective, adverb, and noun, biweekly now means "occurring every two weeks, or sometimes twice a week", so the present definition can be read against the older forms and meanings. The same lexical family is also visible in related forms such as week, weekly, and biennial. The result is a borrowed or transmitted form whose modern spelling carries a compact record of its route into English.