This is the 269th most frequent Croatian word.
jedini
"Jedini" means "the only one" or "sole" in English.
Here, 'jedini' means 'the only one', emphasizing uniqueness.
On je jedini čovjek koji je uspio u tome.
He is the only person who succeeded in that.
In this case, 'jedina' is the feminine singular form, indicating exclusivity of correctness.
Njegova je odluka bila jedina ispravna.
His decision was the only correct one.
Here, 'jedino' is used as a neutral singular form, referring to a single thing desired to be conveyed.