noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   a planet that is between the size of Mercury and Ceres
2. 2
   A habitable planet, such as Earth, that has a surface temperature of 0–50°C, optimal for much terrestrial life.

Synonyms

All synonyms

dwarf planetpsychroplanetthermoplanet

Etymology

From meso- + planet.

Related phrases

habitable planet

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.