mi·​cro·​sphere ˈmī-krə-ˌsfir How to pronounce microsphere (audio)
: a minute sphere
microspherical adjective

Example Sentences

Recent Examples on the Web The microsphere, buffeted by Brownian motion, rolls along the trail picking up one peptide after another. The Physics Arxiv Blog, Discover Magazine, 23 Sep. 2021 The researchers compared this motion to that of a similar microsphere moving over a surface without the lawn of peptides. The Physics Arxiv Blog, Discover Magazine, 23 Sep. 2021 The microsphere activate on contact, releasing extracts on the skin through friction to help replenish lost moisture and keep it there longer. Leada Gore | Lgore@al.com, al, 23 Sep. 2020 Expandable graphite’s disruptive effect is triggered at a slightly higher temperature (160°C) than the 125°-150°C which causes the microspheres to inflate. The Economist, 28 May 2020 Without the microspheres, the flat, white brushstrokes would be imperceptible. Los Angeles Times, 5 Aug. 2019 These clusters of specially coated microspheres dissipate energy by roping nearby spheres into forming identical clusters. Quanta Magazine, 22 Jan. 2014 The catalyst for this rapid process is known are polystyrene microspheres, tiny particles which contain styrene and have a wide range of applications throughout the sciences. David Grossman, Popular Mechanics, 15 Aug. 2018 Available for purchase online, polystyrene microspheres can absorb proteins, be loaded with compounds, and perform any number of scientific tasks. David Grossman, Popular Mechanics, 15 Aug. 2018 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'microsphere.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1894, in the meaning defined above

Time Traveler
The first known use of microsphere was in 1894

Dictionary Entries Near microsphere

Cite this Entry

“Microsphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/microsphere. Accessed 29 May. 2023.

Medical Definition


mi·​cro·​sphere -ˌsfir How to pronounce microsphere (audio)
: a spherical shell that is usually made of a biodegradable or resorbable plastic polymer, that has a very small diameter usually in the micron or nanometer range, and that is often filled with a substance (as a drug or antibody) for release as the shell is degraded

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