This is the 15282nd most frequent Polish word.
skaz
A flaw, blemish, or defect.
Here, 'skaz' is used metaphorically to denote a defect in an abstract sense.
Jego sukcesem był skaz na sterylności życia.
His success bore a trace in the sterility of life.
This usage of 'skaz' indicates a physical imperfection on an object.
Kielich miał drobny skaz na krawędzi.
The goblet had a small flaw on its edge.
In this case, 'skaz' is used figuratively to refer to a complex emotional undertone.