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in-line

American  
[in-lahyn, in-lahyn] / ˌɪnˈlaɪn, ˈɪnˌlaɪn /

adjective

  1. (of an internal-combustion engine) having the cylinders ranged side by side in one or more rows along the crankshaft.

in-line British  

adjective

  1. denoting a linked sequence of manufacturing processes

  2. denoting an internal-combustion engine having its cylinders arranged in a line

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
in line Idioms  

  1. Also, in line with . In conformity or agreement; within ordinary or proper limits. For example, The new policy was intended to keep prices in line with their competitors , or It's up to the supervisor to keep the nurses in line . Also see fall in line .

  2. Also, on line . Waiting behind others in a row or queue. For example, The children stood in line for their lunches , or There were at least 50 persons on line for opera tickets .

  3. in line for . Next in order for, as in He is next in line for the presidency . All of these terms employ line in the sense of “an orderly row or series of persons or objects,” a usage dating from the 1500s.

Etymology

Origin of in-line

First recorded in 1925–30

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The research focused on in-line filtration, a method in which water is first treated with a coagulant and then passed through a sand filter.

From Science Daily • Apr. 20, 2026

Currency was a headwind and North American sales were weak, but the overall adjusted gross margin was slightly ahead of the bank’s estimate with networks margins coming in-line.

From The Wall Street Journal • Apr. 17, 2026

While the official contract cannot explicitly mention the practice of ghostwriting, rewriting, or in-line editing, it can acknowledge revision, commentary, and any form of feedback.

From Slate • Mar. 20, 2026

“An in-line PPI number tomorrow seems neutral or favorable for the economy and markets,” writes Mike Bailey, director of research at FBB Capital Partners.

From Barron's • Feb. 26, 2026

It was the ‘Bullet N°2’ racing car, the first with an eight-cylinder, in-line engine, according to Eugene Hammond.

From "The Teacher’s Funeral" by Richard Peck

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.