This is the 4194th most frequent Polish word.
czerwona
"Red" (feminine form).
Here, 'czerwona' is an adjective describing the noun 'sukienka' (dress) and follows Polish noun-adjective agreement rules.
Czerwona sukienka wisi na wieszaku.
The red dress hangs on the hanger.
In this sentence, 'czerwonej' is the inflected form of 'czerwona' used in the genitive case due to the negation context present in Polish syntax.
Nie mogę znaleźć mojej czerwonej szminki.
I can't find my red lipstick.
Here, 'czerwona' is still an adjective, but it agrees with 'lampka' (light), which is feminine.