Unexplained means still without any account or answer. An unexplained disappearance, unexplained wealth, remains unexplained.
In British law an unexplained wealth order requires somebody to account for assets that do not match their known income, and failing to explain can lose them the property. In science, unexplained is where the interesting work is.
1adjectiveunexplainedStill without any account or answer.
“The police are investigating a series of unexplained fires in the area.”
unexplained is a state.
From un- + explained.
Etymology from Wiktionary, CC BY-SA