biphasic
/bɪˈfeɪzɪk/Definitions
1. adjective
having two phases, especially in a biological cycle or a physiological process
“The biphasic sleep pattern of the two-year-old child includes a long period of deep sleep followed by a short period of lighter sleep.”
2. noun
a substance or mixture that undergoes two phases of change, especially in a chemical reaction
“The biphasic mixture was observed to separate into two distinct layers after several hours.”