I"so*bront (ī"s&osl;*br&obreve;nt), n. [Iso- + Gr. bronth` thunder.] (Meteor.) An imaginary line, or a line on a chart, marking the simultaneous development of a thunderstorm, as noted by observing the time when the thunder is heard at different places.

I"so*bront (ī"s&osl;*br&obreve;nt), n. [Iso- + Gr. bronth` thunder.] (Meteor.) An imaginary line, or a line on a chart, marking the simultaneous development of a thunderstorm, as noted by observing the time when the thunder is heard at different places.