Any of a class of low-density extrasolar planets which have a mass similar to or greater than that of Jupiter but which orbit very close to the parent star.
Origin
1990s; earliest use found in Science.
Definition of hot Jupiter in US English:
hot Jupiter
noun
Astronomy
Any of a class of low-density extrasolar planets which have a mass similar to or greater than that of Jupiter but which orbit very close to the parent star.