also: ねんし
He is mature for his age.
Standard kanji spelling for the common reading としは.
Alternate kanji spelling; also read ねんし, but としは is more common.
Rare reading restricted to this kanji form; としは is the usual reading.
Compound of 年 (とし, 'year') and 端 (は, 'edge, beginning'), literally 'the edge of years', implying the early stage of life or age. The kanji 歯 is an ateji substitution.