Z line

noun

: any of the dark thin bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres

Examples of Z line in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Trains on the 2, 3, A, C, J and Z lines were running at lower speeds in the area. — Joe Ruiz Jr., CBS News, 18 Apr. 2023 More pedestrians than not pause at a street memorial under an elevated section of the J and Z lines in North Brooklyn. — Doreen St. Félix, New Yorker, 8 Nov. 2025 But the AirTrain — which connects with the A/E/J/Z lines and the LIRR — hasn’t been affected. — Stefanie Waldek, Curbed, 30 June 2025 The French luxury footwear brand debuted the Miss Z line in a kaleidoscope of hues of hot pink, aqua, yellow and more at the Christian Louboutin spring 2025 show during Paris Fashion Week. — Karla Rodriguez, Footwear News, 4 Feb. 2026 Apple Photos can handle raw camera files from popular digital cameras, including more recent formats like Canon’s CR3 and Nikon’s NEF for its Z line of mirrorless cameras. — Michael Muchmore, PC Magazine, 29 June 2026

Word History

First Known Use

1916, in the meaning defined above

Time Traveler
The first known use of Z line was in 1916

Rhymes for Z line

See All Rhymes for Z line

Browse Nearby Words

Zlatoust
Z line
zloty
See all Nearby Words

Cite this Entry

“Z line.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Z%20line. Accessed 7 Jul. 2026.

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Medical Definition

Z line

noun
: any of the dark bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres

More from Merriam-Webster on Z line

Britannica.com: Encyclopedia article about Z line

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