biofilm

noun

bio·​film ˌbī-(ˌ)ō-ˈfilm 

: a thin usually resistant layer of microorganisms (such as bacteria) that form on and coat various surfaces

Examples of biofilm in a Sentence

Recent Examples on the Web

These include the ability to form sticky biofilms that anchor them to surfaces, robust DNA repair mechanisms to counter radiation damage, and the capacity to form tough, dormant spores that endure even the most punishing conditions. —Mrigakshi Dixit, Interesting Engineering, 2 Jan. 2026

This problem usually begins in hidden crevices in seals and gaskets, but this nasty biofilm can eventually spread and make your dishwasher unsanitary. —Brandee Gruener, Southern Living, 10 Dec. 2025

An assault on enamel Cavity-causing bacteria also use dietary sugars to make a sticky layer called a biofilm that acts like a fortress attached to the teeth. —Jacqueline Abranches, The Conversation, 2 Dec. 2025

Increase their longevity by sanding down the biofilm lurking on the surface. —Matt Fuchs, Time, 24 Nov. 2025

Word History

First Known Use

1975, in the meaning defined above

Rhymes for biofilm

• film
• microfilm

Medical Definition

biofilm

noun

bio·​film ˈbī-ō-ˌfilm 

: a thin usually resistant layer of microorganisms (as bacteria) that form on and coat various surfaces (as of catheters or water pipes)