疏忽 (shūhu) means to neglect or overlook something due to carelessness or inattention, often with negative consequences. Unlike 忽视 (hūshì), which can imply deliberate ignoring, 疏忽 is always unintentional; it's closer to 忽略 (hūlüè) but emphasizes the carelessness aspect. 遗漏 (yílòu) is more specific to missing an item in a list or process.