IPA: /ʌnˈklɪərɪst/
KK: /ʌnˈklɪrɪst/
The least clear or most difficult to understand.
The instructions were the unclearest I have ever seen, making it hard to follow them.
Comparative: unclearer
Superlative: unclearest
Unclearest → It is formed from "un-" (meaning not) and "clear" (from Old English "cleare", meaning free from darkness or obscurity) and "-est" (a superlative suffix indicating the highest degree). The word "unclearest" means not the clearest or least clear, indicating a lack of clarity in the highest degree.
Think of 'not' ('un-') being added to 'clear' to show something that is the 'least clear' — that's what 'unclearest' means.