fundamental

basic, essential, fundamental, radical, vital

principle, theorem, fundamental, law

名词 fundamental:

1. the lowest tone of a harmonic series
   同义词：fundamental frequency, first harmonic

形容词 fundamental:

1. serving as an essential component
   同义词：cardinal, central, key, primal
2. being or involving basic facts or principles
   同义词：rudimentary, underlying
3. far-reaching and thoroughgoing in effect especially on the nature of something
   同义词：profound

1. There are fundamental differences between your religious beliefs and mine.
   你我的宗教信仰根本不同。
2. If you two are going to marry, I advise that you need to know the fundamentals of cooking.
   如果你们要结婚的话，我建议你们了解烹调的基本知识。
3. A knowledge of economics is fundamental to any understanding of this problem.
   经济知识对于理解这个问题是至关重要的。
4. There is a fundamental difference in attitude between these two politicians.
   这两位政治家的态度有着根本的区别。

fun.da.men.tal

adj.（形容词）

Of or relating to the foundation or base; elementary:
基础的：基础或基本的或与此有关的；根本的：
例句：
the fundamental laws of the universe.
宇宙间的基本规律

Forming or serving as an essential component of a system or structure; central:
主要的：形成或作为系统或结构的重要组成部分的：
例句：
an example that was fundamental to the argument.
论据中的一个主要例证

Of great significance or entailing major change:
十分重要的：极其重要的或主宰重大变化的：
例句：
a book that underwent fundamental revision.
经过重大修订的一本书

Physics
【物理学】
Of or relating to the component of lowest frequency of a periodic wave or quantity.
基波的：周期波或周期量的最低频率的分力的或与此有关的
Of or relating to the lowest possible frequency of a vibrating element or system.
震动因素或体系的最低频率
Music Having the root in the bass:
【音乐】 基音的：
例句：
a fundamental chord.
基音和弦

n.（名词）
Something that is an essential or necessary part of a system or object.
基础：系统或事物极其重要或必不可缺的部分
Physics The lowest frequency of a periodically varying quantity or of a vibrating system.
【物理学】 基频：周期变化量或振动系统的最低频率

【引伸】
fun.damen.tally
adv.（副词）