reniform

A drawing of a section of a human kidney, showing a reniform (sense 1) shape. (The kidneys of small- to moderate-sized mammals are generally of this shape; larger mammals’ kidneys tend to be more lobular.)

Kidney beans (Phaseolus vulgaris) are reniform (sense 1).

The reniform (sense 1) compound eyes of a species of longhorn beetle (family Cerambycidae).

The upper surface of a lumbar vertebra is reniform (sense 1).

The red kuri squash (Cucurbita maxima) has reniform (sense 1.1) leaves.

Learned borrowing from Latin rēnis (the genitive singular of rēn (“kidney”); see further at that entry) + English -form (suffix meaning ‘having the form or shape of’), modelled after New Latin rēnifōrmis (“of seeds: kidney-shaped”).^[1]

• (Received Pronunciation) IPA^(key): /ˈɹɛnɪfɔːm/, /ˈɹiː-/

• Audio (Southern England):

  (file)

• (General American) IPA^(key): /ˈɹɛnəˌfɔɹm/, /ˈɹiː-/, /-nɪ-/
• Hyphenation: ren‧i‧form

reniform (not comparable)

1. (chiefly biology, mineralogy) Synonym of kidney-shaped (“having an approximately circular or elongated ovoid shape with an inward curve or indentation on one side”)

   intussusception with a reniform appearance

   multiple reniform circumscribed fat-containing masses

   • [1745, James Parsons, “Tab. V. Fig. 12. a. Cow-itch, Coughage, or Stinging-Beans.”, in The Microscopical Theatre of Seeds: […], volume I, London: […] F. Needham, […]; and sold by M. Cooper, […], →OCLC, page 201:

     The Bean […] is oval, and not at all reniform'd like the Kidney-Beans.]

   • 1751, John Hill, “Class the Sixth. Order the First. Division the First. Hexandria Monogynia, Having Corollæ Divided into Three Segments, and Cups to Them. [TRADESCANTIA.]”, in A General Natural History: Or, New and Accurate Descriptions of the Animals, Vegetables, and Minerals of the Different Parts of the World; […], volume II (A History of Plants), London: […] Thomas Osborne, […], →OCLC, part III (Plants Called the More Perfect Ones), page 364:

     [T]he antheræ are reniform: the germen is oval, and obtuſely trigonal; […]

   • 1756, Albert Haller [i.e., Albrecht von Haller], “Observation LIX. A Coalition of the Kidnies.”, in Pathological Observations, Chiefly from Dissections of Morbid Bodies, London: […] D. Wilson and T. Durnam, […], →OCLC, page 178:

     In one of the ſegments of the lovver portion of the kidney, there vvas a large reniform Papillæ, in the outer circumference of vvhich a ſmall part of the papillary fleſh vvas vvanting. […] In the oppoſite ſegment, there vvas a fourth reniform Papilla, reſembling the firſt; […]

   • 1799, William Babington, “[Class III. Metals. Order II. Fragile. Genus IV. Cobalt.] Species II. Native Oxyde of Cobalt.”, in A New System of Mineralogy, in the Form of a Catalogue, after the Manner of Baron Born’s Systematic Catalogue of the Collection of Fossils of Mlle. Élénore de Raab, London: […] T[homas] Bensley, […]; and sold by W. Phillips, […]; G. G. and J. Robinsons, […]; and T[homas] Cox, […], →OCLC, page 232:

     The oxyde of cobalt, […] is found either ſuperficial, interſperſed, or in lumps; ſometimes botryoidal or reniform or bearing particular impreſſions.

   • 1861, Richard F[rancis] Burton, “To Ruby Valley”, in The City of the Saints and across the Rocky Mountains to California, London: Longman, Green, Longman, and Roberts, →OCLC, page 570:

     Nothing could be more simple than the furniture. The chairs were either posts mounted on four legs spread out for a base, or three-legged stools with reniform seats.

   1. (botany) Of a leaf: kidney-shaped, with the petiole attached at the notch.

      Coordinate term: obreniform

• obreniform
• semireniform
• subreniform

• renal

• reniform (disambiguation) on Wikipedia.Wikipedia
• “reniform”, in The American Heritage Dictionary of the English Language, 5th edition, Boston, Mass.: Houghton Mifflin Harcourt, 2016, →ISBN.
• “reniform, adj.”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present, reproduced from Stuart Berg Flexner, editor in chief, Random House Unabridged Dictionary, 2nd edition, New York, N.Y.: Random House, 1993, →ISBN.

• informer, reinform

Borrowed from French réniforme.

reniform m or n (feminine singular reniformă, masculine plural reniformi, feminine and neuter plural reniforme)

1. reniform