- The first decade of a century: from 1900 to 1909, 2000 to 2009, etc.
- A nonce word, sometimes avoided because it is a homonym with naughties; it is even sometimes spelled "Naughties". Terms such as at the turn of the century or in the early years of the century are more common. In context, as during that decade or in the immediately following years, or in a list of decades, 1900s/nineteen-hundreds and 2000s is commonly used, but this becomes ambiguous in a broader context, as 1900s more commonly means the entire century, and 2000s may mean the entire millennium. The first decade of the twentieth century is frequently referred to as the Edwardian era in the UK, as it coincides very closely with the reign of King Edward VII.
- Like twenties, etc, the word is sometimes capitalised.
nought (“zero”) + -ies (“plural of -y”), in imitation of the names of other decades (twenties, thirties, etc)