 In the 1950s, he introduced the word circadian, which derives from the Latin about ("circa") a day ("diem").Franz Halberg was nominated several times for the Nobel Prize in Physiology or Medicine.In 1988, and again in 1989, upon invitation by Professor Björn Nordenström of the Karolinska Institute in Sweden, then a member of the Nobel committee, Germaine Cornelissen, close associate of Franz, nominated Franz for the prize, highlighting the different ingredients contributed by Franz in developing the discipline of chronobiology.