Correct spelling, explanation: the root of the word unnamed is name, which comes from the forms onoma and nomen, which used to be Greek and Latin words. The word name, however, entered English from Old English. Unnamed, on the other hand, didn’t appear in English until the 15th century and now it’s a widely used English adjective.

Definition of unnamed:
1. adjective – if the name of something or someone is unknown,
We spent the best holidays of our lives in some unnamed countryside in the east of the country.

Collocations with unnamed:
Collocations with unnamed are: unnamed man, remain unnamed, unnamed illness.
The unnamed man approached me and asked me for my phone number.
The victim of the crime remains unnamed despite the fact the police have been trying to identify him for a few weeks.
In the past, people often died from unnamed illnesses.

Incorrect spelling, explanation: while spelling the word unnamed many users of English tend to omit a double -n letter in this word, which gives an incorrect form unamed. We need a prefix -un and a suffix -ed to form it. The -e letter at the end of the word remains single, but the -n letter has to be doubled so the correct form is unnamed.

Incorrect spelling

Incorrect spelling