n. [ Iso- + Gr. &unr_; weight. ] (Phys. Geog.) A line connecting or marking places upon the surface of the earth where height of the barometer reduced to sea level is the same either at a given time, or for a certain period (mean height), as for a year; an isopiestic line. [ Written also isobare. ] [ 1913 Webster ]

a. (Phys. Geog.) Denoting equal pressure; as, an isobaric line; specifically, of or pertaining to isobars. [ 1913 Webster ]

n. The quality or state of being equal in weight, especially in atmospheric pressure. Also, the theory, method, or application of isobaric science. [ 1913 Webster ]

a. [ Iso + barometric. ] (Phys. Geog.) Indicating equal barometric pressure. [ 1913 Webster ]

n. [ Iso- + Gr. &unr_; deep + &unr_; heat. ] (Phys. Geog.) A line connecting the points on the surface of the earth where a certain temperature is found at the same depth. [ 1913 Webster ]

a. Of or pertaining to an isobathytherm; possessing or indicating the same temperature at the same depth. [ 1913 Webster ]

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. [ Webster 1913 Suppl. ]

n. [ From Gr. &unr_; like-headed. See Iso-, and Cephalon. ] (Art) A peculiarity in the design of bas-relief by which the heads of human figures are kept at the same height from the ground, whether the personages are seated, standing, or mounted on horseback; -- called also isokephaleia. [ 1913 Webster ]

n. [ Iso- + chasm. ] (Phys. Geog.) A line connecting places on the earth's surface at which there is the same mean frequency of auroras. [ 1913 Webster ]

a. Indicating equal auroral display; as, an isochasmic line. [ 1913 Webster ]