A person who is not a member of law enforcement but who pursues and punishes persons suspected of lawbreaking.
[Spanish, watchman, vigilante, from Latin vigilāns, vigilant-, present participle of vigilāre, to be watchful, from vigil, watchful; see weg- in the Appendix of Indo-European roots.]
vig′i·lantism (-lăntĭz-əm), vig′i·lante·ism (-tē-ĭz′əm) n.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.