存疑 is a formal, written verb meaning 'to hold in doubt' or 'to suspend judgment' — literally combining 存 (cún, 'to retain, to keep') and 疑 (yí, 'doubt, suspicion'). Together, they express the active mental stance of deliberately withholding acceptance or conclusion due to insufficient evidence or uncertainty. It implies thoughtful caution rather than mere ignorance or disbelief.

This term is commonly used in academic, legal, journalistic, and analytical contexts — for example, when scholars question a historical claim, judges reserve judgment on contested evidence, or editors flag unverified facts in a report. It carries a neutral-to-cautious tone and is rarely used in casual speech; native speakers typically say 怀疑 (huáiyí) or 不确定 (bù quèdìng) in everyday conversation. 存疑 emphasizes intellectual responsibility: retaining doubt as a provisional, reasoned position pending further verification.