This is the 12788th most frequent Polish word.
nieznacznie
Slightly.
Here, 'nieznacznie' is used as an adverb to indicate a small degree of difference in a comparative sentence.
Góra ta jest nieznacznie wyższa od sąsiedniej.
This mountain is slightly taller than the neighboring one.
In this sentence, 'nieznacznie' serves as an adverb describing the extent to which the action of changing one's opinion occurred.
Nieznacznie zmieniłem swoją opinię po dyskusji.
I slightly changed my opinion after the discussion.
The word 'nieznacznie' here modifies the verb to convey that the improvement was minimal or of little amount.