Rudimentary (adjective)

1. In an early and undeveloped stage; basic and elementary.
2. Lacking complexity or sophistication; primitive.

Origin:

Mid 17th century: from latin rudimentarius, from rudimentum "beginning, foundation" (see rudiment).

Examples:

1. The project was still in its rudimentary stage, and much work remained to be done.
2. The car had only a rudimentary radio, just a simple AM tuner.
3. The robot had a rudimentary understanding of human emotions, it could only recognize basic emotions such as happiness and sadness.
4. He had a rudimentary knowledge of the language, and could only carry on a basic conversation.
5. The cave paintings were considered rudimentary forms of art, but they were an important historical artifact.