Interpreted

A language is considered to be interpreted if the source code is translated on the fly, during execution. When a piece of source code needs to be executed, the interpreter will translate just that bit of source code into machine code.

At it's most basic if you need to run the same piece of source code twice, it will need to be converted to machine code twice; which is a waste of resources. However, most interpreters have optimisations to reduce this resource waste.