---
tag: 0XGCZ4GDZ6
kind: concept
name: Meagre set
aliases: [meager-set, first-category-set]
msc: ["54E52"]
sources:
  - url: https://en.wikipedia.org/wiki/Meagre_set
    locator: lead section
same_as:
  wikidata: Q1747745
  wikipedia: Meagre set
---

## Summary

A meagre subset of a topological space is a countable union of nowhere dense sets.
Meagre sets are small in the sense of Baire category.