This is the 8075th most frequent Russian word.
купала
"Купала" refers to a traditional Slavic festival, Ivan Kupala, celebrating the summer solstice, or can relate to bathing/swimming.
Here, "Купала" is used as part of a proper noun referring to a traditional Slavic holiday, signaling cultural significance.
В ночь на Ивана Купала устраивали праздники с кострами.
On the night of Ivan Kupala, celebrations with bonfires were held.
In this sentence, "купала" is a verb in the past tense form meaning 'bathed,' related to washing or bathing someone or something.
Она купала ребёнка в тёплой ванне.
She bathed the child in a warm bath.
Again, "Купала" refers to the Slavic holiday, showcasing its recurring cultural and traditional context.