Penetrable

Pen"e*tra*ble (?), a. [L. penetrabilus: cf. F. pénétrable.] Capable of being penetrated, entered, or pierced. Used also figuratively.

And pierce his only penetrable part.
Dryden.

I am not made of stones,
But penetrable to your kind entreats.
Shak.

-- Pen"e*tra*ble*ness, n. -- Pen"e*tra*bly, adv.