This is the 65th most frequent Ukrainian word.
однак
"However" or "nevertheless."
In this sentence, "однак" serves as a conjunctive adverb, linking the contrasting idea of her plan to the resulting rain.
Вона планувала вийти на прогулянку, однак пішов дощ.
She planned to go for a walk, however, it started raining.
This use of "однак" introduces a concessive relationship, highlighting the effort without immediate visible outcomes.
Він багато тренується, однак результати поки невідомі.
He trains a lot, yet the results are still unknown.
Here, "однак" connects the assessment of being interesting with the contrasting fact of being somewhat hard to understand.