teens; teenage; ages 10-19
Refers to the age range from 10 to 19, or to people in that age group. Commonly used in demographic and social contexts.
This survey targets teenagers.
Even though she is still in her teens, she is very composed.
tenth generation
Refers to the tenth generation of a family, dynasty, or lineage. Less common in everyday conversation; more often seen in historical or genealogical contexts.
See also: 代
He is protecting the family as the tenth-generation head.
It was an event that attracted many teenagers.
He took over as the tenth-generation head of the long-established shop.
He made his professional debut in his early teens.
She got married while still in her teens.
Kanji spelling; standard in newspapers and formal contexts.
Numerical spelling; very common in statistics, surveys, and casual writing.
Compound of 十 (ten) and 代 (generation, age range). The reading じゅうだい follows standard on'yomi.