This is the 293rd most frequent Ukrainian word.
частина
"Part" or "portion."
The word "частина" is used here to mean a 'part' or 'segment' of a whole, specifically referring to an important aspect of someone's life.
Ця книга стала важливою частиною його життя.
This book became an important part of his life.
Here, "частина" is utilized in a literal sense to refer to a physical section or piece of a puzzle.
Він не зміг скласти цю частину пазла.
He couldn't assemble this part of the puzzle.
In this context, "частина" refers to a segment or portion of an abstract entity, in this case, a task.