'Isothermal' definitions:

Definition of 'isothermal'

From: WordNet
adjective
Of a process or change taking place at constant temperature

Definition of 'Isothermal'

From: GCIDE
  • Isothermal \I`so*ther"mal\, a. [Cf. F. isotherme.] (a) Relating to equality of temperature, or an isotherm. (b) (Phys. Geog.) Having reference to the geographical distribution of temperature, as exhibited by means of isotherms; as, an isothermal line; an isothermal chart. [1913 Webster]
  • Isothermal line. (a) An isotherm. (b) A line drawn on a diagram of energy such that its ordinates represent the pressures of a substance corresponding to various volumes, while the absolute temperature is maintained at a constant value.
  • Isothermal zones, spaces on opposite sides of the equator having the same mean temperature, and bounded by corresponding isothermal lines. [1913 Webster]