Where does the な in 大人 (otona) come from?


As far as I understand, the word 大人 (otona) uses the kanji 大 to represent お
and the kanji 人 to represent と. According to [this
site](http://tangorin.com/kanji/%E4%BA%BA) the readings for 人 do not include
な. Where does the な come from then?




It's [熟字訓]{じゅくじくん}. Excerpt from
[Wiktionary](http://en.wiktionary.org/wiki/jukujikun):

> A Japanese word whose kanji spelling conveys the meaning based on the
> individual characters, but the reading is not directly related to the
> spellling. For example, 大 (“big”, usually read _ō_ in _kun'yomi_ compounds)
> and 人 (“person”, usually read _hito_ in _kun'yomi_ compounds) combine to
> form 大人, meaning “adult” but read as _otona_ instead of the otherwise-
> expected _ōbito_.

We have tons of 熟字訓, e.g. [昨日]{きのう}, [土産]{みやげ}, [二十歳]{はたち} etc. For more, see
[熟字訓 on Wikipedia](http://ja.wikipedia.org/wiki/%E7%86%9F%E5%AD%97%E8%A8%93).




It's [熟字訓]{じゅくじくん}. Excerpt from
[Wiktionary](http://en.wiktionary.org/wiki/jukujikun):

> A Japanese word whose kanji spelling conveys the meaning based on the
> individual characters, but the reading is not directly related to the
> spellling. For example, 大 (“big”, usually read _ō_ in _kun'yomi_ compounds)
> and 人 (“person”, usually read _hito_ in _kun'yomi_ compounds) combine to
> form 大人, meaning “adult” but read as _otona_ instead of the otherwise-
> expected _ōbito_.

We have tons of 熟字訓, e.g. [昨日]{きのう}, [土産]{みやげ}, [二十歳]{はたち} etc. For more, see
[熟字訓 on Wikipedia](http://ja.wikipedia.org/wiki/%E7%86%9F%E5%AD%97%E8%A8%93).

