Function define_property 

pub fn define_property<T>(
    target: &Object<T>,
    property_key: &JsValue,
    attributes: &Object,
) -> Result<bool, JsValue>
where
    Object<T>: ErasableGenericBorrow<Object<JsValue>>,

The static Reflect.defineProperty() method is like Object.defineProperty() but returns a Boolean.

MDN documentation