deu·te·ri·um 
(d-tîrē-əm, dy-)
(d-tîrē-əm, dy-)n.
A naturally occurring isotope of hydrogen, H-2, having one proton and one neutron in the nucleus.
[DEUTER(O)- + -IUM.]
- insurance
- insure
- insured
- insurer
- insurgence
- insurgency
- insurgent
- insurgently
- insurmountability
- insurmountable
- insurmountableness
- insurmountably
- insurrection
- insurrectional
- insurrectionary
- insurrectionism
- insurrectionist
- insusceptibility
- insusceptible
- insusceptibly
- INT
- int.
- intact
- intact dilation and extraction
- intactly