Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun planetary_nebula

1 sense of planetary nebula

Sense 1
planetary nebula -- (a nebula that was once thought to be a star with its planets but is now thought to be a very hot star surrounded by an expanding envelope of ionized gases that emit a fluorescent glow because of intense radiation from the star)
       => nebula -- (an immense cloud of gas (mainly hydrogen) and dust in interstellar space)