Standard Lemma guide

zeptojoule

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.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

No pronunciation record was provided for this word.

noun

Meaning 1

An SI unit of energy equal to 10−21 joules. Symbol: zJ

Definition source: English Wiktionary via Wiktextract

Topics: metrology

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

From zepto- + joule.

Word forms

Inflections and variants

zeptojoules — plural

Word family

Derived and related words

Derived: zJ

Related: none provided

Semantic map

Other relationships

Sources

Where this information comes from

Wiktionary data was expanded into structured fields by Wiktextract. Matching Princeton WordNet definitions and semantic relationships, plus CMUdict ARPABET pronunciations, are merged into this same canonical word page.

Wiktionary text is credited to English Wiktionary contributors under Creative Commons Attribution-ShareAlike 4.0. The source entry and revision history URL, legal text, and the complete attribution and reuse instructions are collected on the site-wide Sources, credits & licenses page.

Changes made: Wiktionary markup was removed and matching senses were grouped; WordNet and CMUdict evidence was merged into the canonical word page. Source quotations with separate cited works are not republished.

The page is served entirely from a local, versioned copy; opening it makes no upstream request or external navigation.