# pilus

> English word · Noun

## Definitions
1. A hair.
2. A hairlike appendage found on the cell surface of many bacteria.
3. A bacterial protein that has several biochemical functions.

## Etymology
Borrowed from Latin pilus (“hair”). Doublet of pile.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/pilus