[{"Bold_text": "adjective", "List Items": ["of or relating to a biorhythm regular biological cycle occurring once every 24 hours, such as waking and sleeping: Compare infradian ( def ) infradian ( def ), ultradian ( def ) ultradian ( def ).Exposure to blue light at night can disrupt your circadian rhythm, making your biological clock think it's earlier in the day rather than time for bed.He is doing research related to the circadian cycling of hormones."]}]