ammonoid

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noun

An extinct cephalopod of the subclass †Ammonoidea (including ammonites).

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Scrabble 13

Meanings

nounammonoid (plural ammonoids)

plural ammonoids

  1. An extinct cephalopod of the subclass †Ammonoidea (including ammonites).

    Although the extinct externally shelled cephalopods ammonoids have an extensive fossil record, their soft tissues are very poorly known and, like extinct and living nautiloids, they are largely presumed to not have possessed an ink sac.

    2017 August 9, Mark Carnall, “Why do cephalopods produce ink? And what's ink made of, anyway?”, in The Guardian
adjectiveammonoid (comparative more ammonoid, superlative most ammonoid)

comparative more ammonoid · superlative most ammonoid

  1. Characteristic of an ammonite.

    Literally tens of pence with an ammonoid fossil to highlight how bling bling the world of palaeontology has become

    2016 November 9, Mark Carnall, “Is palaeontology a waste of public money?”, in The Guardian

Synonyms & antonyms

nounone of the coiled chambered fossil shells of extinct mollusks

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Also see

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

From the scientific name Ammonoidea, equivalent to Ammon + -oid.

Full word history & related roots →
Cite this entry
APA

ammonoid. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/ammonoid

MLA

“ammonoid.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ammonoid. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “ammonoid,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/ammonoid.

Source: ammonoid on Wiktionary, CC BY-SA 4.0.