Warning
Advice, Caution
noun, する verb, の adjective
When you announce something to warn somebody, you're warning them. Sometimes you're just trying to give them some helpful advice.
けいこく
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
借りた金を早く返すよう警告した。
I advised him that he should pay back money he borrowed soon.
あの選手はどの試合でも必ず警告のイエローカードを出されるね。
That player gets a yellow card warning in every game.
警告を無視するつもりなのか？
Do you intend to ignore this warning?