Longman Dictionary of Contemporary English
biorhythms
noun
EXAMPLES FROM CORPUS
▪ Arthur Schlesinger keeps writing about cycles of history, while New Age psychotherapists rhapsodize about biorhythms.
▪ It had more to do with biorhythms or the moon or something.
▪ The biorhythms program is simple and easy to use for those who know the subject but are not computer boffins.
Wiktionary
biorhythms
n. (plural of biorhythm English)
Usage examples of "biorhythms".
You ever go to a mall or an amusement park and see one of those machines where you drop in a quarter and it gives you your biorhythms, or your emotional state, or something like that?
Ever since they'd arrived at Zanthus he'd been on the verge, time stretched up here, knocking biorhythms along with the rest of normality.