Teething refers to the process of new teeth rising or erupting through the gums. Teething can begin in infants as young as 2 months of age, even though the first tooth usually does not appear until about 6 months of age. Some dentists have noted a family pattern of early, average, or late teethers.
noble metal. 1. any of a number of metals, as gold, silver, mercury, or platinum, that resist oxidation when heated in air, and solution by inorganic acids. But now, at the first and yet final trial, she is proved and found to be of noble metal. There was a noble metal collarâabout thirty-two, the size would have been, on the usual scale.
Noble gas. Noble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). The noble gases are colourless, odourless, tasteless, nonflammable gases.