iso-, is-

(Greek: equal; by extension: same, similar, alike; normally used as a prefix)

Used in numerous terms, nearly all scientific; denoting: equality, similarity, uniformity, or identity; the second element being properly and usually of Greek origin, rarely of Latin [the proper prefix in the latter case being equi-]. In biology, denoting for or from different individuals of the same species). For a large list of iso- opposites or antonyms, see aniso-.

isostatic
Subjected to equal pressure from every side being in hydrostatic equilibrium, as a body submerged in a liquid at rest.
isotach, isotachy
A line on a weather chart connecting points of equal windspeed.
isotherapy
The treatment of a disease by administering the active causative agent of the same disease.
isothere, isotheral
A line connecting places on the earth’s surface having the same mean summer temperature.
isotherm
1. Having the same temperature.
2. Of, pertaining to, indicating, or corresponding to equal temperatures.
3. Occurring at a constant temperature; pertaining to or involving a constancy of temperature with time.
4. A line connecting points having the same temperature in a vertical section of any part of the sea.
5. A line on a graph showing the relationship between variables, especially pressure and volume, at a constant temperature.
isothermal
1. Indicating equality or consistency of temperature.
2. A line connecting places on the earth’s surface having the same mean, or constant, temperature.
3. A curve or formula showing the relationship between two variables; such as, pressure and volume, when the temperature is held constant.
isothermic
A reference to or descriptive of having a constant temperature.
isothermobath
A line connecting points having the same temperature in a diagram of a vertical section of the ocean.
isothermognosis
An abnormal perception in which stimulations of pain, heat, and cold are all felt as heat.
isothymia
Emotional equilibrium.
isotimic
Pertaining to a quantity that has equal value in space at a particular time.
isotonic
1. Having uniform tension, as the fibers of a contracted muscle.
2. Of a solution, having the same osmotic pressure as the fluid phase of a cell or tissue.
isotonicity
1. The quality of possessing and maintaining a uniform tone or tension.
2. Normal tension under pressure or stimulus.
3. The property of a solution in being isotonic.
isotope (s), isotopes (pl)
1. One of two or more forms of a chemical element having the same properties and the same atomic number but different mass numbers or atomic weights.
2. Isotope literally means, "the same place, an equal place".
3. Elements that occupy the same place in the periodic table of the elements, sharing common chemical properties, but having different atomic weights (depending on the number of neutrons carried by each nucleus).

The decay rates of a number of radioactive isotopes are valuable clocks for archeologists, paleontologists, and geologists.

isotoxic
Producing toxic effects in individuals of the same species as the originating individual; characteristic of or pertaining to a homeotoxin.

Inter-related cross references, directly or indirectly, involving word units dealing with "equal, identical, same, similar": auto-; emul-; equ-, equi-; homeo-; homo-; pari-; peer; rhomb-; syn-; tauto-.