• IPA: /pɪθ/

pith (uncountable)

1. (botany) The soft, spongy substance in the center of the stems of many plants and trees.
2. The spongy interior substance of a feather or horn.
3. (anatomy) The spinal cord; the marrow.
4. (botany) The albedo of a citrus fruit.
5. (figuratively) The essential or vital part; force; energy; importance.

   The pith of my idea is that people should choose their own work hours.

   • c. 1599–1602, William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act III, scene i], line 88, page 265 ↗:

     And enterprizes of great pith and moment

6. (figuratively) Power, strength, might.

• (essential or necessary part) core, essence, general tenor, gist, heart, heart and soul, inwardness, kernel, marrow, meat, nitty-gritty, nub, quintessence, soul, spirit, stuff, substance; See also Thesaurus:gist

• pith helmet
• pithy
• pith and substance

• French: moelle
• German: Mark
• Italian: midollino
• Portuguese: medula
• Russian: сердцеви́на
• Spanish: médula, medula, pulpa

• French: moelle, cœur
• Russian: суть
• Spanish: médula, medula, meollo

pith (piths, present participle pithing; past and past participle pithed)

1. (transitive) To extract the pith from (a plant stem or tree).
2. (transitive) To kill (especially cattle or laboratory animals) by cutting or piercing the spinal cord.

• IPA: /paɪθ/

pith (not comparable)

1. The ordinal form of the number pi.

   The pith root of pi is approximately 1.439...

pith (plural piths)

1. One divided by pi.