This is the 88th most frequent Polish word.
prawie
Almost.
Here, 'prawie' is used to mean 'almost', expressing that not everyone but nearly all attended the party.
Prawie wszyscy przyszli na przyjęcie.
Almost everyone came to the party.
In this example, 'prawie' expresses something being nearly in a state, referring to the light levels as being close to darkness.
Było prawie ciemno, kiedy wróciliśmy do domu.
It was almost dark when we returned home.
In this sentence, 'prawie' conveys the idea of being on the verge of liking something but not quite.