Japanese edit

For pronunciation and definitions of こうこう – see the following entries.
口腔
[noun] the oral cavity
Alternative spelling
こうくう
甲香
[noun] the operculum of a shell; often that belong to a veined rapa whelk
[noun] a fragrance made up of such a ground up operculum
交媾
[noun] sexual intercourse
[verb] have sex
坑口
[noun] pithead; minehead, entrance to a coal mine
孝行
[noun] filial piety
[adjective] dutiful
[verb] to be good to one's parents
後攻
[noun] going second (in an offensive–defensive competition)
[verb] to go second (in an offensive–defensive competition)
皇考
[noun] (respectful) current emperor's deceased paternal father
[noun] (respectful) grandfather
航行
[noun] sailing
[verb] to sail, to cruise
高校
[noun] (education) high school; senior high school
港口
[noun] harbor entrance
煌々
[adjective] brilliant, radiant, sparkling
膏肓
[noun] vital organs
鏗鏗
[adjective] (literary) ringing through (of the sound of bells, etc)
Alternative spelling
鏗々
(This term, こうこう, is the hiragana spelling of the above terms.)

(The following entries are uncreated: 工高, 公行, 公侯, 交交, 考校, 行行, 抗衡, 拘拘, 昂昂, 杲杲, 哈哈, 後行, 後考, 後項, 郊行, 香香, 浩浩, 耿耿, 降紅, 黄口, 惶惶, 皓皓, 硬膏, 硬鋼, 遑遑, 鉱坑, 構桁, 皞皞, 鴻荒, 鴻溝, 曠曠.)