乱雲 is read as らんうん (ranun) and means rain cloud.
らんうん
ranun
らんそううん
nimbostratus
せきらんうん
cumulonimbus cloud
かさいせきらんうん
pyrocumulonimbus (cloud)
らんよう
abuse
らんぼう
rape
みだれる
to lapse into chaos (due to war, etc.)
みだす
to throw into disorder
らんざつ
disorder
らっぷ
boisterous dance
らんりつ
standing (for election) in (excessively) large numbers
らんばい
underselling
らんぱつ
random firing