(1):

(a.) Admitting passage; capable of being penetrated by another body or substance; permeable; as, a pervious soil.

(2):

(a.) Capable of being penetrated, or seen through, by physical or mental vision.

(3):

(a.) Capable of penetrating or pervading.

(4):

(a.) Open; - used synonymously with perforate, as applied to the nostrils or birds.