プログレッシブ和英中辞典(第4版)の解説
はんだくてん【半濁点】
a small circle attached to kana letters beginning with the [h]-sound to show they are to be pronounced as [p]
日本語の解説|半濁点とは
a small circle attached to kana letters beginning with the [h]-sound to show they are to be pronounced as [p]