deuterium

noun

deu·​te·​ri·​um dü-ˈtir-ē-əm 

also dyü-

: an isotope of hydrogen that has one proton and one neutron in its nucleus and that has twice the mass of ordinary hydrogen

—symbol D

called also heavy hydrogen

Examples of deuterium in a Sentence

Recent Examples on the Web

Because protium, deuterium, and tritium share the exact same chemical structure, standard chemical filters cannot tell them apart. — Aman Tripathi, Interesting Engineering, 7 Aug. 2026

The comet contains far more heavy hydrogen—in the form of an isotope called deuterium, which has one neutron and one proton—than any local space rock, a quality that tends to point to colder environs. — Joseph Howlett, Scientific American, 22 June 2026

Word History

Etymology

New Latin, from Greek deuteros second

First Known Use

1933, in the meaning defined above

Phrases Containing deuterium

• deuterium oxide

Rhymes for deuterium

• agrobacterium
• corynebacterium
• mycobacterium
• bacterium
• delirium
• imperium
• puerperium
• venereum
• cyanobacterium
• magisterium
• ministerium

Kids Definition

deuterium

noun

deu·​te·​ri·​um d(y)ü-ˈtir-ē-əm 

: the hydrogen isotope that is twice the mass of ordinary hydrogen

called also heavy hydrogen

Medical Definition

deuterium

noun

deu·​te·​ri·​um d(y)ü-ˈtir-ē-əm 

: an isotope of hydrogen that has one proton and one neutron in its nucleus and that has twice the mass of ordinary hydrogen

called also heavy hydrogen