The adjective obscure means not well known, or only known by a few people. It also refers to something that is not clear to the understanding. This word can act as a verb which means to make something dark, gloomy, dim, or difficult to understand.

Synonyms are ambiguous, arcane, conceal, or cover.

The word origins from Middle English, Anglo-French (12th Century) obscuroscur meaning “dark, clouded, gloomy, dim, not clear” and directly from Latin obscurus meaning “dark, dusky, shady” figuratively “unknown, unintelligible, hard to discern”.

His use of obscure jargon made the story confusing.

Because she’s naturally intelligent, she always speaks in obscure language so I don’t always understand her.

It looks like it’s about to rain, the sun is obscured by the clouds.