The story
From galactic + habitable zone.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: the zone in a disk galaxy lying within the disk which is neither too far from the core so as to be lacking in heavier elements, nor too close to the core as to experience excessive exposures to supernovae, where intelligent life may develop Full definition →
From galactic + habitable zone.
Etymology from Wiktionary, CC BY-SA 4.0.