Definition of polytropic in US English:

polytropic

adjective

  • 1Capable of taking various courses of action; adaptable, versatile.

  • 2Of a bee or other insect: visiting the flowers of many species.

  • 3Physics. Relating to or characterized by the constraint that pressure and volume vary in such a way that a specific heat remains constant, or (more widely) by the constraint that pressure, temperature, entropy, and volume vary in such a way that a particular property remains constant. Also (rarely) as noun: a graph showing such a variation.

  • 4Astronomy. Of or relating to a star modelled as a sphere in hydrostatic equilibrium such that at a given radial distance the pressure P and density ρ are related by P = Kρ(n + 1)/n, where K is a constant.

Origin

Mid 19th century; earliest use found in Fraser's Magazine for Town and Country. From ancient Greek πολύτροπος turning many ways, versatile, etc., (also) much-travelled (epithet of Odysseus in Homer's Odyssey (goes to post-classical Latin polytropus); from πολυ- + -τροπος: see -trope) + -ic.