What Does Expressive Mean?

Expressive is an adjective that can be used for somebody who is able to show his thoughts and feelings well. The word not only used for a person but can also be used to describe a particular organ of a person's body. The following context can better describe the meaning of the word: Chelsea has wonderfully expressive eyes.
The word can also be used for an art form which makes you think that it is expressing an idea. You can use it as is used in the following sentence: The expressive power of music.  

When the word 'expressive' is conjugated with 'of something' it conveys the idea of a thing that exists as an expression of something. The following sentence can better describe the term as it is used in the context: Each and every gesture is expressive of the painter's sincerity.