A thief; someone who steals. Similar to 泥棒 but somewhat dated or literary.
昔話には、盗人が教訓的に扱われる場面が多い。
In folktales, thieves are often treated in a moralizing way.
財布を取られたが、盗人は人混みに消えてしまった。
My wallet was taken, but the thief disappeared into the crowd.