1.Definition: being or involving basic facts or principles
"The fundamental laws of the universe", "A fundamental incompatibility between them"
2.Definition: 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"
3.Definition: serving as an essential component
"An example that was fundamental to the argument", "Computers are fundamental to modern industrial structure"