英和和英

an unknown place

His whereabouts is unknown

He is missing.

an unspecified location

destination unknown

His whereabouts is unknown.

address unknown

an indefinite or unknown location

of no fixed abode

to set foot on an unknown place

He has no fixed abode―no fixed home.

an unfamiliar place

His whereabouts is unknown.

unexplored regions

lacking a particular location

an unknown source

in a manner that is unclear

a place somewhere in an unidentified location

location

（人なら）He is missing―（金などなら）―The money is not yet accounted for.

to be missing

an unrelated position

not informed

a sightly location

an unknown island

Address unknown.

an unenlightened state

not being in a specified place

discover the location of

（風説）an unfounded rumour―a groundless rumour―（説）―an ill-grounded theory―（報）―unauthentic news―mythical information