プログレッシブ和英中辞典(第4版)の解説
みっこく【密告】
secret information；《口》 a tip-off; a tip
密告する inform ((against, on))；《口》 tip off ((about, that))
匿名で彼がここにいると密告があった
We received 「anonymous information [an anonymous tip] that he was here.
誰かが警察に私のことを密告した
Somebody informed the police against [on] me.／Somebody tipped off the police about me.
密告者
an informer; a betrayer