This is the 2289th most frequent Polish word.
tle
The Polish word "tle" means "background."
This use of 'tle' refers to a background, indicating a setting against which something is seen.
Na tle nieba widać chmury.
Against the sky, the clouds are visible.
'Tle' in this context conveys comparison or a basis for evaluation.
Na tle poprzednich wyników, te są niezwykle imponujące.
In comparison to previous results, these are extremely impressive.
Here, 'tle' designates a backdrop against which something stands out.