雷公 is read as らいこう (raikou) and means thunder.
らいこう
raikou
らいうん
thundercloud
いかずち
anger
かみなり
らい
らいめい
thunder
らいう
thunderstorm
らいどう
following blindly
らいはつ
outbreak of thunder
fame
らいさんすいぎん
mercury fulminate
かみなりおやじ
snarling old man
らいでん
thunder and lightning