(Internet) a troll; someone who disturbs or sabotages online discussions by posting provocative or disruptive messages.
掲示板に荒らしが来てスレッドがめちゃくちゃになった。
A troll showed up on the forum and the thread got ruined.
荒らしの投稿は無視するのが一番だ。
Ignoring troll posts is the best approach.
モデレーターが荒らしを即座に削除した。
The moderator immediately deleted the troll's post.
As a suffix/noun indicating making a mess of or vandalizing something — e.g. causing havoc in a place.
夜中に畑荒らしの被害が増えている。
There have been increasing incidents of people vandalizing fields at night.
公園荒らしをした犯人が捕まった。
The person who vandalized the park was caught.
As a suffix meaning robbery or holdup — e.g. burglary of apartments (アパート荒らし).
深夜にアパート荒らしの被害が相次いだ。
There were repeated incidents of apartment burglaries late at night.
警察は近隣の荒らし事件を関連付けて捜査している。
The police are investigating nearby robbery incidents as related.
A person who vandalizes or robs — a vandal or robber.
暴動で店を荒らした荒らしが数人逮捕された。
Several vandals who ransacked shops during the riot were arrested.
夜中に入って家を荒らした荒らしがいたと通報があった。
There was a report that someone had broken in at night and ransacked a house.