pentagonal

From pentagon + -al.

• IPA^(key): /pɛnˈtæɡənəl/

• Audio (Canada):

  (file)

• Rhymes: -æɡənəl

pentagonal (comparative more pentagonal, superlative most pentagonal)

1. Of, relating to, or shaped like a pentagon.
   • 1850, John Radford Young, An introductory treatise on mensuration, in theory and practice, page 115:

     If the base be a triangle, it is called a triangular prism; if a square, a square prism; if a pentagon, a pentagonal prism; and' if the base is any irregular figure, it is called an irregular prism : ...

   • 2018, B Özüdoğru, “Phylogenetic position, taxonomy, distribution, and conservation status of the rare and poorly-known Noccaea rosularis, the generic type of Masmenia …”, in Phytotaxa:

     Seed micromorphology:—Seed coat is laticostate. Epidermal cells are elliptical to irregularly pentagonal. Cell walls are thickened mostly at the corners, the boundaries are raised […]

pentagonal (plural pentagonals)

1. Something having the shape of a pentagon.
   • 1941, Steel, volume 109, page 59:

     Speaking of protection, note that not only are the end pentagonals surrounded by a generous air space, but the entire instrument is insulated, […]

   • 1993, Michael Pfrommer, Metalwork from the Hellenized East: Catalogue of the Collections, page 188:

     The pentagonals with the flowers and the leaves of the central calyx are gilded all over, as is the inner lip of the vessel.

From pentàgon +‎ -al.

• IPA^(key): (Central) [pən.tə.ɣuˈnal]
• IPA^(key): (Balearic) [pən.tə.ɣoˈnal]
• IPA^(key): (Valencia) [pen.ta.ɣoˈnal]
• Rhymes: -al

pentagonal m or f (masculine and feminine plural pentagonals)

1. pentagonal

• Alcover, Antoni Maria; Moll, Francesc de Borja (1963), “pentagonal”, in Diccionari català-valencià-balear (in Catalan)
• “pentagonal” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• “pentagonal”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “pentagonal”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007

From pentagone +‎ -al.

• IPA^(key): /pɛ̃.ta.ɡɔ.nal/

• Audio (France (Lyon)):

  (file)

pentagonal (feminine pentagonale, masculine plural pentagonaux, feminine plural pentagonales)

1. pentagonal

• “pentagonal”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012

From pentágono (“pentagon”) +‎ -al (“of or relating to”).^[1][2]

• Hyphenation: pen‧ta‧go‧nal

pentagonal m or f (plural pentagonais)

1. pentagonal (of, relating to, or shaped like a pentagon)

• pentágono

• “pentagonal”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “pentagonal”, in Dicionário inFormal (in Portuguese), 2006–2026
• “pentagonal” in Dicionário Aberto based on Novo Diccionário da Língua Portuguesa de Cândido de Figueiredo, 1913
• “pentagonal”, in Michaelis Dicionário Brasileiro da Língua Portuguesa (in Portuguese), São Paulo: Editora Melhoramentos, 2015–2026, →ISBN

From pentagon +‎ -al.

pentagonal m or n (feminine singular pentagonală, masculine plural pentagonali, feminine/neuter plural pentagonale)

1. pentagonal

From pentágono +‎ -al.

• IPA^(key): /pentaɡoˈnal/ [pẽn̪.t̪a.ɣ̞oˈnal]
• Rhymes: -al
• Syllabification: pen‧ta‧go‧nal

pentagonal m or f (masculine and feminine plural pentagonales)

1. pentagonal

   Synonym: pentágono

• “pentagonal”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025