Zeptojoule

noun

noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    An SI unit of energy equal to 10⁻²¹ joules. Symbol: zJ

    "When a bundle with a drag coefficient of 200 nN · sec · m⁻¹ (Howard and Hudspeth, 1988) produced a 25 nm, triangle-wave twitch 5 msec in total duration (Fig. 12A), the energy dissipated against viscous drag was ~100 zJ (a zeptojoule is 10⁻²¹ J)."

Example

More examples

"When a bundle with a drag coefficient of 200 nN · sec · m⁻¹ (Howard and Hudspeth, 1988) produced a 25 nm, triangle-wave twitch 5 msec in total duration (Fig. 12A), the energy dissipated against viscous drag was ~100 zJ (a zeptojoule is 10⁻²¹ J)."

Etymology

From zepto- + joule.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.