_A definition of a term is a statement of its meaning by enumerating its characteristic attributes._

That the enumeration must be in terms of its distinguishing or characteristic attributes is implied in the derivation of the term _definition_. The attributes must establish limits or bounds, just as a line fence limits a land owner’s possessions. To indicate that man is a creature possessing the power of locomotion, sense of sight and ability to eat, is surely not a definition, as the marks are not characteristic of men only. These attributes set no boundary between man and horse, consequently the statement is a faulty _description_ of man, not a _definition_. But when the enumeration includes such attributes as power of speech, rationality and ability to laugh, then does the description become a definition. To put it differently: A definition is a description of a term by means of its distinguishing attributes. This statement may be considered a definition of man, though somewhat faulty: “A man is a creature who is rational and who possesses the power of speech and ability to laugh.”

A Class Room Logic — Part 54

We have learned that general terms when connotative may be used extensionally or intensionally.

A Class Room Logic — Part 54

A definition indicates the _intensional_ nature of a term, while a statement which points out the _extensional_ nature of a term is known as logical division. More briefly: A definition is an _intensional_ statement of the nature of the term, while logical division is an _extensional_ statement of the nature of the term.

A Class Room Logic — Part 54

To illustrate: The following statements are definitions:

(1) A dog is a domesticated quadruped of the genus canis and given to barking.

(2) A quadrilateral is a rectilinear figure of four sides.

(3) Soil is a substance composed of pulverized rock and decayed vegetable matter in which plants will grow.

The following represent Logical Division:

(1) Dogs are divided into hounds, terriers, bull, etc.

(2) The kinds of quadrilaterals are trapeziums, trapezoids and parallelograms.

(3) The various soils are loam, sand, clay, muck, etc.

Generally speaking there are three kinds of definitions, namely, (1) Etymological, (2) Descriptive, (3) Logical.[5]

(1) _An etymological definition is one based upon the derivation of the term._