obscure

His lamp shall be put out in obscure darkness.

I found myself in an obscure wood.

The lock was of a kind that Watt could not pick. Watt could pick simple locks, but he could not pick obscure locks.

an obscure passage or inscription; The speaker made obscure references to little-known literary works.

Of all the medical monsters Peter Hotez could have set out to slay, the Yale University researcher could not have chosen a more wily and obscure villain than the hookworm.

i need to be REALLY careful to not use any obscure words. otherwise my tweets might end up on a wiktionary page