chal·co·gen 
(kălkə-jən)
(kălkə-jən)n.
Any of the elements appearing in Group 6a of the periodic table, sharing certain chemical properties; oxygen, sulfur, selenium, tellurium, polonium, or element 116.
[Greek khalkos, copper + -GEN, since many of the important ores of copper, such as chalcopyrite, contain chalcogens.]
- nonfiction
- nonfictional
- nonfiction novel
- nonflammable
- nonfood
- nongonococcal urethritis
- nongraded
- non grata
- nonhero
- non-Hodgkin lymphoma
- non-Hodgkin's lymphoma
- noni
- nonidentical
- nonillion
- nonillionth
- nonimmigrant
- noninductive
- noninertial frame
- non-insulin-dependent diabetes
- non-insulin-dependent diabetes mellitus
- nonintervention
- noninterventionist
- noninvasive
- noninvolvement
- nonissue