inconnu in English:

Smallpox was unknown to Native Americans.

Although most islands in the ocean have been mapped, the ocean floor is generally unknown.

Many great thinkers who were unknown while alive became famous after death.

his parents are unknown.

The symbol "X" usually stands for an unknown quantity in mathematics.

There are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know.

When I opened my eyes again, all of a sudden an unknown lady was standing right in front of me.

Sophie had been looking forward to getting another letter from the unknown sender.

A change of opinions is almost unknown in an elderly military man.

For all his genius, he is as unknown as ever.

The vast majority of high school students I know can't read an unknown word and pronounce the letters in the right order, let alone pronounce it correctly or naturally.

In other words, physical obstacles, perhaps unknown to the original surveyor and engineer, requiring alterations to be made in order to surmount them.

Look up unknown words in a dictionary

Author unknown

He looked out into a crowd of unfamiliar faces.

I am unfamiliar with the customs of this country.

If you come across an unfamiliar word, look it up in your dictionary.

You should look up all unfamiliar words in a dictionary.

The landscape is unfamiliar to me.

We drove through unfamiliar territory.

The cat was scared by an unfamiliar noise.

The travellers need someone to guide them through the unfamiliar jungle.

Jerry decided to leave the motorway and take an unfamiliar route to the airport. No wonder we got lost.

The voice on the phone was unfamiliar to me.

The tribe worships its ancestors and speaks its own language, and speaks an unfamiliar language.

At first there will be many unfamiliar words and grammatical forms, but you don't have to be afraid.

I wonder if that restaurant accepts unfamiliar customers.