This is the 17405th most frequent Russian word.
теннисистке
"Теннисистке" means "to the female tennis player" in English.
Here, 'теннисистке' is the dative singular form of 'теннисистка,' indicating the recipient of the action (the award).
Теннисистке дали заслуженную награду за первое место.
The tennis player was given a well-deserved award for first place.
In this sentence, 'теннисистке' is the prepositional singular form of 'теннисистка,' being used after the preposition 'с' to indicate the person being spoken with.
Мы часто разговариваем с теннисистке о её тренировках.
We often talk with the tennis player about her training.
Here, 'теннисистке' is the instrumental singular form of 'теннисистка,' demonstrating that a match belongs to the player in question.