We define a word more, not by stating what it represents, but more by restricting what it means. To de-fine is to say what a word does not mean. Modern science is distinguished by two important traits. The supreme example of exactness in language is found in mathematics. A mathematician defines a concept such as point in geometry in such a manner that leaves you no latitude for confusing it with some other entity.
Point is defined by delimiting meaning, by strictly excluding all other possibilities.
The Pythagoreans came to power 2500 years ago. They left a legacy of exacting mathematical language. But the Pythagoreans were not scientists. They expressed and imposed a strong disdain for experimental method. They reasoned that all that was knowable or useful was derivable from logical thought and mathematical language.