- sulfurous (adj.)
- also sulphurous, 1530s, from Latin sulphurosus or a native formation from sulfur + -ous. Related: Sulfurously; sulphurously.
- sulfurous (adj.)
- also sulfurous, 1520s, "of the nature of brimstone," from sulfur + -ous. Hence figurative use with suggestions of hellfire (c.1600). Scientific chemistry sense is from 1790. Earlier in the "brimstone-like" sense was sulphurious (late 15c.).