Standard Lemma guide

feynmanium

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

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Pronunciation

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1

noun

Meaning 1

The hypothetical chemical element with atomic number 137.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

From Feynman + -ium. After Richard Feynman, who used a back-of-the-envelope calculation using classical physics to determine that element 137 is the last stably neutrally charged element, as larger elements would need electrons traveling faster than light to become neutral. (This problem goes away when relativity is considered.)