Half-baked (adjective)

1. Not thought out or developed fully.
2. Not well-considered or planned.
3. Not fully cooked or done.

Origin:

From the phrase "half-cooked".

Examples:

1. The half-baked plan was not well thought out and was quickly discarded.
2. The idea was half-baked and needed more work before it could be implemented.
3. The cake was removed from the oven because it was half-baked.
4. The half-baked scheme was doomed to failure.
5. The half-baked proposal was met with resistance from the board members.