1,418,386 entries with English definitions from over 300 languages

Browse: Global alphabet • All languages • Topical index • Grammatical index

a A b B c C d D e E f F g G h H i I j J k K l L m M n N o O p P q Q r R s S t T u U v V w W x X y Y z Z

Appendices • Abbreviations • Thesaurus • Rhymes • Frequency lists • Phrasebooks Welcome to the English language Wiktionary, a collaborative project to produce a free-content multilingual dictionary. Designed as the lexical companion to Wikipedia, the encyclopaedia project, Wiktionary has grown beyond a standard dictionary and now includes a thesaurus, a rhyme guide, phrase books, language statistics and extensive appendices. We aim to include not only the definition of a word, but also enough information to really understand it. Thus etymologies, pronunciations, sample quotations, synonyms, antonyms and translations are included. Wiktionary is a wiki, which means that you can edit it, and all the content is dual-licensed under both the Creative Commons Attribution-ShareAlike 3.0 Unported License as well as the GNU Free Documentation License. Before you contribute, you may wish to read through some of our Help pages, and bear in mind that we do things quite differently from other wikis. In particular we have strict layout conventions and inclusion criteria. Learn how to start a page, how to edit entries, experiment in the sandbox and visit our Community Portal to see how you can participate in the development of Wiktionary. , Word of the day for October 3 curfew n

1. (historical) A regulation in feudal Europe by which fires had to be covered up or put out at a certain fixed time in the evening.
2. The evening bell, which continued to be rung in many towns after the regulation itself became obsolete.
3. Any regulation requiring people to be off the streets and in their homes by a certain time.
4. The time when such restriction begins.

About Word of the Day • Archive • Nominate a word • RSS feed

Behind the scenes

Community Portal

A page containing everything you wanted to know about Wiktionary.

Discussion rooms

A collection of pages for the discussion of Wiktionary and the words it contains.

Things to do • Tutorial • Guidelines Index

Latin: a A b B c C d D e E f F g G h H i I j J k K l L m M n N o O p P q Q r R s S t T u U v V w W x X y Y z Z Accented: à-ç è-ý À-Ü Āā-Řř Śś-Žž Greek: Α-Κ Λ-Σ Τ-Ω α-θ ι-ρ σ-ω Ἀἀ-Ῥῥ Cyrillic: А-Н О-Я а-б в-г д-з и-к л-м н-о п р-с т-ц ч-я(-ә) Armenian: Ա-դ ե-ճ մ-ֆ Hebrew: ‏‏א-ו‎ ז-ל‎ מ-צ‎ ק-ת‎ Arabic: ‏‏ا-ب‎ ت-س‎ ش-م‎ ن-ی‎ Khmer: ក – ឱ Japanese: ぁ-げ こ-ぱ ひ-ケ コ-ヶ Han Characters: 一 促 冱 卙 哪 圱 天 存 崃 弿 愷 捇 新 杁 Korean: ㄱ 가 나 다 라 마 바 사 아 자 차 카 타 파 하

Random word • New entries

In mathematics, a proof is a convincing demonstration (within the accepted standards of the field) that some mathematical statement is necessarily true. Proofs are obtained from deductive reasoning, rather than from inductive or empirical arguments. That is, a proof must demonstrate that a statement is true in all cases, without a single exception. An unproved proposition that is believed to be true is known as a conjecture.

The statement that is proved is often called a theorem. Once a theorem is proved, it can be used as the basis to prove further statements. A theorem may also be referred to as a lemma, especially if it is intended for use as a stepping stone in the proof of another theorem.

Proofs employ logic but usually include some amount of natural language which usually admits some ambiguity. In fact, the vast majority of proofs in written mathematics can be considered as applications of rigorous informal logic. Purely formal proofs, written in symbolic language instead of natural language, are considered in proof theory. The distinction between formal and informal proofs has led to much examination of current and historical mathematical practice, quasi-empiricism in mathematics, and so-called folk mathematics (in both senses of that term). The philosophy of mathematics is concerned with the role of language and logic in proofs, and mathematics as a language.