Consisting wholly, or in part, of pith; abounding in pith; as, a pithy stem; a pithy fruit.

Having nervous energy; forceful; cogent.

Spongy; e.g., culm of Saccharum.

concise and full of meaning; "welcomed her pithy comments"; "the peculiarly sardonic and sententious style in which Don Luis composed his epigrams"- Hervey Allen

in a pithy sententious manner; "she expressed herself pithily"

having meaningful substance and point

Sometimes used in the sense of having a large pith and little wood.