This is the 2531st most frequent Polish word.
odrą
"Odrą" is the instrumental form of "Odra," the name of the Oder River in Poland.
In this sentence, 'odra' refers to the name of the river Oder, a proper noun.
Odra to jedna z największych rzek w Polsce.
The Oder is one of the largest rivers in Poland.
In this sentence, 'odra' is used as a noun to mean 'measles,' a contagious viral infection.
W zeszłym wieku w Europie odnotowano epidemię odry.
In the last century, an epidemic of measles was recorded in Europe.
Here, 'odrą' is used in the instrumental case to signify 'on/by the Oder River.'