noun (plural protogalaxies)Astronomy
- A vast mass of gas from which a galaxy is thought to develop.More example sentences
- According to current models, that's not enough time to allow for the formation of either the quasars that illuminate the atomic gas or the protogalaxies that harbor the first stars.
- The protogalaxy probably has since coalesced into a giant elliptical galaxy, he says.
- Those that are still around us bear the imprint of the chemical composition of the protogalaxy in their atmospheres, like living fossils of a bygone era in the history of the Earth.
More definitions of protogalaxyDefinition of protogalaxy in:
- The US English dictionary