- 下落不明 xiàluòbùmíng missingwhereabouts are unknown or unaccounted for
- 不明不白 bùmíngbùbái dubiousobscure; dubious; shady
- 来历不明 láilìbùmíng unknown origin(idiom) of unknown origin; of dubious background
- 不明飞行物 bùmíngfēixíngwù UFOunidentified flying object (UFO)
- 去向不明 qùxiàngbùmíng missingwhereabouts unknown or unaccounted for
- 来路不明 láilùbùmíng dubioushaving a suspicious or questionable background or provenance
- 死因不明 sǐyīnbùmíng unexplained deathunknown cause of death
- 不明事理 bùmíngshìlǐ unreasonablenot understanding things; devoid of sense
- 不明就里 bùmíngjiùlǐ unawarenot understanding the actual situation or the underlying details of a matter
- 不明确 bùmíngquè indefinitenot clearly defined, settled, or determined
- 不明觉厉 bùmíngjuélì impressively obscurealthough I don't understand it, it seems pretty awesome (Internet slang)