De Facto Definition

dĭ făktō, dā

adjective

Existing in actuality, especially when contrary to or not established by law.

De facto segregation; a de facto government.

American Heritage

In fact. Description of a person or action that exists for all intentions and purposes, but which lacks official legitimacy.

Webster's New World Law

In fact or in practice; in actual use or existence, regardless of official or legal status. (Often opposed to de jure.)

Although the United States currently has no official language, it is largely monolingual with English being the de facto national language.

Wiktionary

Antonyms:

noun

Existing or being such in actual fact or for all practical purposes, though not by legal establishment, official recognition, etc.

A de facto government.

Webster's New World

(Australia, New Zealand) A legally undeclared spouse.

Wiktionary

adverb

(modal) In practice; in actual use or existence, regardless of official or legal status.

Wiktionary

other

(legally undeclared spouse): common law wife.

Wiktionary

Other Word Forms of De Facto

Singular:

de facto

Plural:

de-factos

Latin dē factō dē from, according to factō ablative of factum fact

From American Heritage Dictionary of the English Language, 5th Edition
From Latin de facto, de (“from”) + ablative of factum (“fact, deed, act”)

From Wiktionary