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.

They overwhelmed their visitors in the second half, with Amy Cokayne, Moloney-MacDonald and Jess Breach crossing over before Packer bagged her second of the afternoon.

From BBC • Apr. 25, 2026

Israeli military body Cogat says approximately 1,150 people have left Gaza via the crossing over the past two months and that the same number have entered Gaza.

From BBC • Apr. 7, 2026

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

From Barron's • Dec. 17, 2025

Twenty captives were crossing over Israel’s border to jubilant homecomings, but Bipin wasn’t among them.

From The Wall Street Journal • Oct. 15, 2025

I shuffle quickly sideways, one foot crossing over the other, squinting to see through the semidarkness.

From "Divergent" by Veronica Roth

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