horizontal
adjective
hor·i·zon·tal
ˌhȯr-ə-ˈzän-tᵊl
ˌhär-
1
2
: relating to, directed toward, or consisting of individuals or entities of similar status or on the same level
horizontal mergers
horizontal hostility
3
medical
: relating to or being transmission (as of a disease) by physical contact or proximity in contrast with inheritance
horizontal transmission of the hepatitis B virus
Genes are normally inherited from parents, but they can also be inserted into a genome by viruses, plasmids, and other foreign agents—a phenomenon called horizontal transfer.—Stephan Reebs
compare vertical sense 4
horizontal
noun
Cite this Entry
“Horizontal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/horizontal. Accessed 1 Sep. 2026.
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