twenty-one-year-old
twenty-one-year-old
UK[ˌtwɛnti wʌn jɪər əʊld]US[ˌtwɛnti wʌn jɪr oʊld]
adj
Being twenty-one years of age.
n
A person who is twenty-one years of age.
Morpheme Breakdown
twenty
one
year
old
twenty
group of twenty
one
one
year
year
old
aged, ancient
Etymology
The compound "twenty-one-year-old" is a modern English construction built from native Germanic elements to precisely denote age. Its first element, "twenty," originates from the Old English 'twēntig', a cardinal number meaning a set of two tens. The hyphenated "one" follows, from the Old English 'ān', to specify the exact count beyond the decade. These numerals are then linked to the unit "year," from Old English 'ġēar', and finally to the adjective "old," from Old English 'eald', describing a state of being. The entire phrase functions as a single lexical unit, its hyphenated spelling reflecting its role as a fixed compound modifier or noun, a logical and transparent method in English for creating specific age descriptors from fundamental number and time concepts.
Analysis
Structure: twenty + one + year + old
- twenty: From Old English 'twēntig', meaning 'group of twenty', from 'twēn-' (two) + '-tig' (group of ten).
- one: From Old English 'ān', meaning 'one', from Proto-Germanic 'ainaz'.
- year: From Old English 'ġēar', meaning 'year', from Proto-Germanic 'jērą'.
- old: From Old English 'eald', meaning 'aged, ancient', from Proto-Germanic 'aldaz'.
Examples
She is a twenty-one-year-old graduate student.
The law applies to every twenty-one-year-old in the country.
He bought a car for his twenty-one-year-old son.