crossing over

American

noun

Genetics.

the interchange of corresponding chromatid segments of homologous chromosomes with their linked genes.

crossing over British

noun

biology the interchange of sections between pairing homologous chromosomes during the diplotene stage of meiosis. It results in the rearrangement of genes and produces variation in the inherited characteristics of the offspring See also linkage

"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

crossing over Scientific

/ krô′sĭng-ō′vər /

The exchange of genetic material between homologous chromosomes that occurs during meiosis and contributes to genetic variability.

Etymology

Origin of crossing over

First recorded in 1910–15

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.

See Examples For:

crossing over

At this level, bitcoin is close to crossing over the year-low set last week.

From The Wall Street Journal ● Jul. 1, 2026

He said the flight took a route down along Saudi Arabia, before "crossing over Israel".

From BBC ● Mar. 6, 2026

Gold traded up 0.8% Friday, and is less than $50 away from crossing over the $5,000-per-ounce threshold for the first time.

From The Wall Street Journal ● Jan. 23, 2026

Illia Issaiev hated it when his family fled the fighting by crossing over into Russia.

From Barron's ● Dec. 17, 2025

But she ignored me, her arms crossing over her chest as she stood a little taller and looked at Callaway.

From "Glitch" by Laura Martin

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