An Engineered language is a constructed language used to help experiment in logic, philosophy, and linguistics.

There are three types of Engineered language:

• Philosophical languages are made to follow philosophical principles. They are often oligosynthetic, an more extreme kind of polysynthesis. This means that they make all their words from only a few really simple words. aUI is a famous philosophical language.
• Logical languages are made to be unambiguous. Lojban is a famous logical language.
• Experimental languages are made for test hypotheses in linguistics. They are usually made to test the Sapir-Whorf hypothesis. Toki Pona, Lojban, and Láadan are famous experimental languages.