Ill-conceived (adjective)

1. Having been planned or thought out in a poor or faulty manner.
2. Having been formed with a poor or incorrect understanding of the subject.

Origin:

Compound of "ill" meaning bad or incorrect and "conceived" meaning planned or thought out.

Examples:

1. The ill-conceived project was doomed from the start.
2. The campaign was ill-conceived and ultimately failed.
3. His ill-conceived plan to take over the company was foiled by the board of directors.
4. The play was ill-conceived and received poor reviews.
5. The ill-conceived strategy resulted in a catastrophic loss.