This is the 14962nd most frequent Turkish word.
sağanakla
"Sağanakla" means "with/through a downpour."
In this sentence, 'sağanakla' is used to describe the tool/cause through which something happens, indicating 'with/through the downpour'.
Sağanakla çimenler hızla ıslanmaya başladı.
The grass rapidly started getting wet with the downpour.
Here, 'sağanakla' specifies the condition/context of the action of running home, emphasizing the state of being in a downpour.
Sağanakla eve koşarken ayakkabılarım çamura bulandı.
While running home through the downpour, my shoes got covered in mud.
In this instance, 'sağanakla' indicates accompaniment or simultaneity, showing that the coolness came together with the occurrence of the downpour.