What is the thing written in grey that sometimes shows up in the macOS Sierra dictionary app?


In the macOS Sierra dictionary app, sometimes when I look up a word, there is
sometimes this thing that's in grey written on the right of the word that I
searched. For example, 管理人:

[![enter image description
here](https://i.stack.imgur.com/TyK1F.png)](https://i.stack.imgur.com/TyK1F.png)

The thing written in grey is くわんー. What does this mean?

Other examples:

[![enter image description
here](https://i.stack.imgur.com/6CwXw.png)](https://i.stack.imgur.com/6CwXw.png)

[![enter image description
here](https://i.stack.imgur.com/JUarB.png)](https://i.stack.imgur.com/JUarB.png)

[![enter image description
here](https://i.stack.imgur.com/pMH8D.png)](https://i.stack.imgur.com/pMH8D.png)

[![enter image description
here](https://i.stack.imgur.com/mPLXk.png)](https://i.stack.imgur.com/mPLXk.png)

I observed that sometimes the "ー" is on the right, sometimes on the left,
sometimes on both sides and sometimes it does not appear at all. And I became
even more confused.

I know that grey text is used to show the "old" forms of some words, like
言う→言ふ:

[![enter image description
here](https://i.stack.imgur.com/naJj2.png)](https://i.stack.imgur.com/naJj2.png)

I thought things like 卵巣癌、更新、検討 are quite new. Maybe this grey text is
something else?




It is archaic form of writing called
[歴史的仮名遣い](https://en.m.wikipedia.org/wiki/Historical_kana_orthography). It was
not until November 16, 1946 that Japan began using modern writing
form([現代仮名遣い](https://en.m.wikipedia.org/wiki/Modern_kana_usage)). For that
reason 歴史的仮名遣い was widely used those days, and today in Japan you can
sometimes see literature written then. That is why modern dictionaries have
the old spelling.

"ー" is used to show the part is written in the same way of modern Japanese.
For example, _ーさうー_ for 卵巣癌(らんそうがん) means it is written as _らんさうがん_ in
歴史的仮名遣い.




It is archaic form of writing called
[歴史的仮名遣い](https://en.m.wikipedia.org/wiki/Historical_kana_orthography). It was
not until November 16, 1946 that Japan began using modern writing
form([現代仮名遣い](https://en.m.wikipedia.org/wiki/Modern_kana_usage)). For that
reason 歴史的仮名遣い was widely used those days, and today in Japan you can
sometimes see literature written then. That is why modern dictionaries have
the old spelling.

"ー" is used to show the part is written in the same way of modern Japanese.
For example, _ーさうー_ for 卵巣癌(らんそうがん) means it is written as _らんさうがん_ in
歴史的仮名遣い.

