- capable of being penetrated.
Origin of penetrable
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
early 15c., "penetrating," from Latin penetrabilis "penetrable, vulnerable," from penetrare (see penetrate). Meaning "capable of being penetrated" is attested from 1530s; figurative use by 1590s. Related: Penetrability.
Online Etymology Dictionary, © 2010 Douglas Harper