What phrase names the area of sky obscured by the Milky Way?

The phrase for the area of sky obscured by the Milky Way is the Zone of Avoidance.

This region lies along the Milky Way’s galactic plane, where foreground stars, gas, and interstellar dust obscure distant galaxies at visible wavelengths. The result is an apparent gap in optical galaxy catalogues, not an actual emptiness in space. Roughly 20% of the extragalactic sky is affected in visible light.

Astronomers have reduced the problem by observing at longer wavelengths. Infrared surveys can penetrate much of the dust, while radio observations—especially searches for neutral hydrogen through its 21-centimeter emission—can reveal galaxies hidden from optical surveys. Maffei 1 and Maffei 2, for example, were discovered in this obscured region through infrared observations.

The term has an interesting history: astronomer Richard Proctor called it the “Zone of Few Nebulae” in 1878, reflecting the shortage of catalogued nebulae near the Milky Way. The modern name describes an observational blind spot, not a boundary or hole in the Galaxy.