Meanings
nounhydrogen line (plural hydrogen lines)
plural hydrogen lines
- astronomya spectral line of atomic hydrogen having a wavelength of about 21cm; used extensively in radio astronomy
Cite this entry
APA
hydrogen line. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/hydrogen%20line
MLA
“hydrogen line.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/hydrogen%20line. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “hydrogen line,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/hydrogen%20line.
Source: hydrogen line on Wiktionary, CC BY-SA 4.0.