A pithy phrase or statement is brief but full of substance and meaning. Proverbs and sayings are pithy; newspaper columnists give pithy advice.
The root of this word is pith, which refers to the spongy tissue in plant stems, or the white part under the skin of citrus fruits. Pith is also used figuratively to refer to the essential part of something: They finally got to the pith of the discussion. Pith descends from Middle English, from Old English pitha "the pith of plants." In the adjective pithy, the suffix –y means "characterized by."