Princeton's WordNet

1. fundamental(noun)

   any factor that could be considered important to the understanding of a particular business

   "fundamentals include a company's growth, revenues, earnings, management, and capital structure"

2. fundamental, fundamental frequency, first harmonic(adj)

   the lowest tone of a harmonic series

3. cardinal, central, fundamental, key, primal(adj)

   serving as an essential component

   "a cardinal rule"; "the central cause of the problem"; "an example that was fundamental to the argument"; "computers are fundamental to modern industrial structure"

4. fundamental, rudimentary, underlying(adj)

   being or involving basic facts or principles

   "the fundamental laws of the universe"; "a fundamental incomatibility between them"; "these rudimentary truths"; "underlying principles"

5. fundamental, profound(adj)

   far-reaching and thoroughgoing in effect especially on the nature of something

   "the fundamental revolution in human values that has occurred"; "the book underwent fundamental changes"; "committed the fundamental error of confusing spending with extravagance"; "profound social changes"

Kernerman English Learner's Dictionary

1. fundamental(adjective)ˌfʌn dəˈmɛn tl

   relating to what is most basic and important

   the fundamental difference between us; to make fundamental changes

Wiktionary

1. fundamental(Noun)

   A leading or primary principle, rule, law, or article, which serves as the groundwork of a system; essential part, as, the fundamentals of linear algebra.

2. fundamental(Adjective)

   Pertaining to the foundation or basis; serving for the foundation. Hence: Essential, as an element, principle, or law; important; original; elementary; as, a fundamental truth; a fundamental axiom.

   One of the fundamental reasons I can't give birth is that I am, in fact, a man.

Origin: From fundamentalis, from fundamentum, from fundare, from fundus

Webster Dictionary

1. Fundamental(adj)

   pertaining to the foundation or basis; serving for the foundation. Hence: Essential, as an element, principle, or law; important; original; elementary; as, a fundamental truth; a fundamental axiom

2. Fundamental(noun)

   a leading or primary principle, rule, law, or article, which serves as the groundwork of a system; essential part, as, the fundamentals of the Christian faith

• fundamenteelAfrikaans
• أصْلي ، جَوْهَري ،أوَّلي، أساسيArabic
• фундаменталенBulgarian
• fundamentalPortuguese (BR)
• podstatný, základníCzech
• grundlegendGerman
• afgørende; fundamentalDanish
• βασικός, θεμελιώδηςGreek
• fundamentalSpanish
• põhilineEstonian
• اساسیFarsi
• perustavanlaatuinenFinnish
• fondamentalFrench
• בְּסִיסִיHebrew
• मूलभूतHindi
• osnovan, bitan, temeljniCroatian
• alapvetőHungarian
• sangat pentingIndonesian
• grundvallar-, undirstöðu-Icelandic
• fondamentaleItalian
• 基本的なJapanese
• 기본이 되는Korean
• esminisLithuanian
• būtisks; pamata-Latvian
• asasMalay
• fundamenteelDutch
• grunnleggende, fundamentalNorwegian
• zasadniczyPolish
• اساسیPersian
• اساسیPashto
• fundamentalPortuguese
• fundamentalRomanian
• совершенно необходимыйRussian
• základnýSlovak
• temeljnega pomenaSlovenian
• fundamentalanSerbian
• fundamental, grundläggandeSwedish
• ที่เป็นพื้นฐานThai
• temel, esasTurkish
• 十分重要的，基本的，基礎的Chinese (Trad.)
• основний; істотнийUkrainian
• اساسیUrdu
• cơ bản; chủ yếuVietnamese
• 十分重要的，基本的，基础的Chinese (Simp.)