poly·​cy·​clic ˌpä-lē-ˈsī-klik How to pronounce polycyclic (audio) -ˈsi- How to pronounce polycyclic (audio)
: having more than one cyclic component
especially : having two or more rings in the molecule

Examples of polycyclic in a Sentence

Recent Examples on the Web The material contains aromatic hydrocarbons that include nitrogen, a subgroup called polycyclic aromatic nitrogen heterocycles. Carl Engelking, Discover Magazine, 17 June 2014 Scientists found varying degrees and concentrations of toxic pollutants including heavy metals such as nickel and copper; polycyclic aromatic hydrocarbons; arsenic; and explosive compounds. Tim Newcomb, Popular Mechanics, 27 Oct. 2022 When the collisional shock wave sweeps over that carbon, the atoms rearrange themselves into complicated molecules called polycyclic aromatic hydrocarbons (PAHs). Phil Plait, Scientific American, 25 Oct. 2022 During that time, scientists believe the ship has been polluting the surrounding waters with nickel, copper, arsenic, explosives and chemicals found in fossil fuels known as polycyclic aromatic hydrocarbons, or PAHs. Sarah Kuta, Smithsonian Magazine, 19 Oct. 2022 In the samples with the highest concentrations of pollutants, Van Landuyt and her colleagues found microbes known to degrade chemicals called polycyclic aromatic hydrocarbons, which occur naturally in coal, crude oil and gasoline. Denise Chow, NBC News, 18 Oct. 2022 That testing found concerning levels of toxic contaminants, including arsenic and polycyclic aromatic hydrocarbons, at roughly two dozen of those sites. Shane Loeffler, ProPublica, 1 Sep. 2022 Researchers found that remaining Birmingham residents were exposed to so many pollutants — such as cancer-causing polycyclic aromatic hydrocarbons — that breathing the air was equivalent to smoking two and a half packs of cigarettes a day. Shane Loeffler, ProPublica, 1 Sep. 2022 The only byproduct is oxygen in contrast to carbon monoxide, polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VO VO -1.2%Cs) from other methods. Ian Palmer, Forbes, 17 Aug. 2022

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

Word History


poly- + cyclic entry 1

First Known Use

1869, in the meaning defined above

Time Traveler
The first known use of polycyclic was in 1869

Dictionary Entries Near polycyclic

Cite this Entry

“Polycyclic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polycyclic. Accessed 21 Jun. 2024.

Medical Definition


poly·​cy·​clic ˌpäl-i-ˈsī-klik How to pronounce polycyclic (audio) -ˈsik-lik How to pronounce polycyclic (audio)
: having more than one cyclic component
especially : having two or more usually fused rings in a molecule
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