This is the 1726th most frequent Dutch word.
uiterst
Extremely; utmost; very.
Here, 'uiterst' is used as an adverb to intensify the adjective 'zorgwekkend' (worrying), meaning 'extremely'.
De situatie is uiterst zorgwekkend.
The situation is extremely worrying.
In this sentence, 'uiterst' serves as an adverb to add emphasis to the adjective 'aardig' (kind), signifying 'extremely'.
Zij is uiterst aardig tegen iedereen.
She is extremely kind to everyone.
This usage of 'uiterst' acts as an adjective, describing a location as 'extreme' or 'outermost'.