Oneties vs. Twenties

Onetiesnoun

(nonce) The second decade of a century: the 1910s, the 2010s, etc. The tens.

Twentiesnoun

plural of twenty

Twentiesnoun

The decade of the 1820s, 1920s, 2020s, etc.

Twentiesnoun

The decade of one's life from age 20 through age 29.

‘The waiter was in his twenties.’;

Twentiesnoun

the time of life between 20 and 30

Twentiesnoun

the decade from 1920 to 1929