This is the 6891st most frequent Spanish word.
descalzas
"Descalzas" means "barefoot" in English.
Here, 'descalzas' is an adjective modifying 'las niñas', indicating that they are barefoot while playing. 'Descalzas' agrees in gender (feminine) and number (plural) with 'las niñas'.
Las niñas están jugando descalzas en el jardín.
The girls are playing barefoot in the garden.
In this context, 'descalzas' describes the condition of the people walking, emphasizing being without shoes. Again, it matches the subject in gender and number.
Siempre caminamos descalzas por la playa al atardecer.
We always walk barefoot along the beach at sunset.
Here, 'descalzas' relates to the state of the individuals after performing the action of taking off their shoes, showing a resultant state. It adapts to the gender and number of those referred to.