This is the 12064th most frequent German word.
un
The German word "un" is not a standalone word; it is a prefix meaning "un-" or "not" in English, used to form negatives or opposites (e.g., "unbekannt" = "unknown").
In this sentence, 'Un' is a dialectal reduction of 'Und', which means 'And'.
Un das ist der Plan.
And this is the plan.
Here, 'un...klar' is a prefix 'un-' used in German to denote negation or opposite, paired with 'klar'.
Ich fühl' mich so unklar heute.
I feel so unclear today.
In this case, 'unzugänglich' uses the prefix 'un-' to negate the root word 'zugänglich', forming an adjective.