IPA: //ʌnˈneɪməbəl//
KK: /ʌnˈneɪməbəl/
Something that cannot be named or described with words.
The beauty of the landscape was so profound that it felt unnamable.
Unnamable → It is formed from "un-" (meaning not) and "name" (from Old English "nama", meaning a word by which a person or thing is known) and the suffix "-able" (meaning capable of). The word "unnamable" means not capable of being named or without a name.
Think of something that is 'not' ('un-') able to be 'named' ('name') — that's why it is called unnamable.