English edit

Etymology edit

Uncertain. Possibly from the Latin infra (below) and diēs (a day) with the English suffix -an. Compare circadian, ultradian, and infra etc.

Adjective edit

infradian (not comparable)

  1. Cyclical with a periodicity significantly longer than 24 hours, that is, less frequent than circadian.

Usage notes edit

The comparative "more infradian" is not used, in contrast to the comparative "more ultradian".

See also edit

Anagrams edit