This is the 17938th most frequent Polish word.
środa
"Środa" means "Wednesday" in English.
Here, "środa" is used as the proper noun referring to the weekday Wednesday.
Środa jest dniem tygodnia.
Wednesday is a day of the week.
In this sentence, "środa" refers to a specific past occurrence of Wednesday in a temporal context.
W zeszłą środę poszedłem na spacer.
Last Wednesday, I went for a walk.
Here, "środa" is used to refer to a future event occurring on Wednesday.