Biduous derives from Latin bīduus, associated with a two-day duration.
English record
Historical dictionaries record English use from the nineteenth century.
Why it remained rare
The ordinary phrase two-day is simpler and more productive.
Frequently asked questions
What does biduous mean?
It means lasting or continuing for two days.
Is biduous a real word?
Yes. It is a rare historical English adjective with Latin roots.
How is it pronounced?
Approximately BID-yoo-us.
Is it the same as dubious?
No. Dubious means doubtful.
Does it always mean forty-eight hours?
No. It can refer to two calendar days.
Can it describe a flower?
Yes. Older dictionary evidence uses it for flowers lasting two days.
Is it common today?
No. Two-day is much more common.
Should it be defined for readers?
Yes, especially outside historical or specialist writing.