syn·​ap·​sis | \ sə-ˈnap-səs How to pronounce synapsis (audio) \
plural synapses\ sə-​ˈnap-​ˌsēz How to pronounce synapses (audio) \

Definition of synapsis

: the association of homologous chromosomes that is characteristic of the first meiotic prophase

Examples of synapsis in a Sentence

Recent Examples on the Web Thermoses of coffee stand ready to keep the synapses firing. Richard Brookhiser, National Review, "The Way We Work Now," 23 Jan. 2020 To create a connectome at the scale of the human brain—which contains about 86 billion neurons and 100 trillion synapses—would be a massive effort. Courtney Linder, Popular Mechanics, "Google's 3D Map of a Fly Brain Is Beautiful," 23 Jan. 2020 The researchers assumed that the tumour synapses would be a random occurrence. Heidi Ledford, Scientific American, "Cancer Cells Have “Unsettling” Ability to Hijack the Brain’s Nerves," 20 Sep. 2019 His son Clark Hunt, who now runs the family’s sports empire, talked about how his father’s synapses made the connection. Cheryl Hall, Dallas News, "A 98-cent toy played a key role in giving the Super Bowl its name," 26 Jan. 2020 Neurons firing action potentials that affect the downstream cells they are wired to (via synapses) are one type of mechanism, as are electronic circuits, made of transistors, capacitances, resistances and wires. Christof Koch, Scientific American, "Will Machines Ever Become Conscious?," 1 Dec. 2019 Cellular timekeepers rhythmically prep areas around the synapses in anticipation of building synaptic proteins during slumber. Emily Willingham, Scientific American, "Sleep Deprivation Shuts Down Production of Essential Brain Proteins," 10 Oct. 2019 These inputs are mind-expanding, creating new synapses and elevating our thinking and performance. Josh Linkner, Columnist, Detroit Free Press, "What are you feeding your mind? Hopefully not the mental equivalent of junk food," 14 Dec. 2019 When combined with beta-amyloid, Fyn is over-activated, which triggers a destruction of connections between nerve cells (synapses) in the brain. Mayo Clinic News Network,, "Alzheimer’s treatments: What’s on the horizon?," 11 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'synapsis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of synapsis

1895, in the meaning defined above

History and Etymology for synapsis

New Latin

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Time Traveler for synapsis

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The first known use of synapsis was in 1895

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Statistics for synapsis

Last Updated

15 Feb 2020

Cite this Entry

“Synapsis.” Dictionary, Merriam-Webster, Accessed 28 Feb. 2020.

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More Definitions for synapsis


syn·​ap·​sis | \ sə-ˈnap-səs How to pronounce synapsis (audio) \
plural synapses\ -​ˌsēz How to pronounce synapses (audio) \

Medical Definition of synapsis

: the association of homologous chromosomes with chiasma formation that is characteristic of the first meiotic prophase and is held to be the mechanism for genetic crossing-over

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