Unfounded (adjective)

1. Not having a basis in fact or reality; without foundation or justification.
2. Not based on or supported by evidence.

Origin:

Un + founded.

Examples:

1. The accusations against him were unfounded and he was cleared of any wrongdoing.
2. The rumors were unfounded and there was no truth to them.
3. The decision was based on unfounded assumptions and was later proved to be wrong.
4. The claim that the company was insolvent was unfounded and it was later revealed that it was in a strong financial position.
5. The allegations of abuse were found to be unfounded after an investigation.