See also: りゅうが

Japanese edit

For pronunciation and definitions of りゅうか – see the following entries.
流下
[noun] flowing down
[verb] flow down
琉歌
[noun] ryūka
硫化
[noun] (chemistry) sulphuration
[verb] (chemistry) sulphurate
(This term, りゅうか, is the hiragana spelling of the above terms.)