やな感じ

>groovy --version
Groovy Version: 1.0-jsr-05-SNAPSHOT JVM: 1.5.0_05-b05
>type Person.groovy
class Person {
        def @Property name
        def age
}

>type Demo.groovy
def p = new Person(name:"Jeremy", age:16)
println p.dump()

>groovy Demo.groovy
Demo.groovy: 1: unable to resolve class Person
 @ line 1, column 9.
   def p = new Person(name:"Jeremy", age:16)
           ^

1 Error

>groovyc Person.groovy
>groovy Demo.groovy
<Person@12f0999 name=Jeremy age=null>