/ˌɛkspoʊˈnɛnʃəl'feɪz/

noun

the second of four main phases of growth that a bacterial population undergoes in a closed system (e.g. batch culture). Occurs directly after lag phase. The growth curve exhibits an exponential rate of increase in cell numbers. Growth rate at this time is constant and maximal given the environment and growth conditions.

New Latin, from expōnent & phasis