Translation

• to strictly prohibit

Examples

• 这房间內严禁吸烟。
  Smoking is not allowed in this room.
• 严禁卖淫嫖娼，赌博，吸毒，酗酒滋事等违法犯罪活动！
  Prostitution, gambling, the use of narcotic substances, drunkenness, disorder, and all other illegal activities are STRICTLY FORBIDDEN.