This is the 4573rd most frequent Polish word.
losu
"Losu" means "fate" or "destiny" (genitive singular form of "los").
In this sentence, 'losu' refers to 'fate' or 'destiny' in a possessive form to indicate something related to 'our' future or predetermined outcomes.
Pomaganie innym jest pokazem dobroci naszego losu.
Helping others is a display of the kindness of our fate.
Here, 'losu' signifies 'fate' or 'destiny' in a possessive form, indicating ownership or association with the concept of fate being discussed.
Ciężka praca i determinacja mogą zmienić bieg losu.
Hard work and determination can change the course of fate.
In this instance, 'losu' again represents 'fate' or 'destiny,' contextualized as a factor influencing the subject's emotional state.