a type of nebula that is observed by its blocking of radiation from other sources
nebula
dark nebula in American English
noun
Astronomy
a cloud of interstellar gas and dust that absorbs and thus obscures the light from stars behind it, appearing as a dark patch in front of a bright nebula or in an otherwise bright area of sky
Also called: absorption nebula
Word origin
[1930–35]This word is first recorded in the period 1930–35. Other words that entered Englishat around the same time include: DNA, cloverleaf, kickback, preset, saddle stitch