1. without a cause or reason; happening or existing without any apparent justification or explanation
Usage: formal or literary

Examples

• His causeless anger toward his friend surprised everyone.
• The causeless fear that gripped her made no logical sense.
• She dismissed his complaints as causeless and unfounded.
• The accident seemed causeless, with no clear explanation for what went wrong.
• His causeless optimism persisted despite the difficult circumstances.
• The causeless delay in the project frustrated the entire team.