1. relating to or involving a secret plan or agreement to do something unlawful or harmful
2. suggesting or characterized by a tendency to believe in conspiracy theories
Usage: informal

Examples

• The conspiratorial meeting was held in secret to avoid detection.
• He spoke in a conspiratorial whisper, as if sharing a dangerous secret.
• The group's conspiratorial behavior raised suspicions among law enforcement.
• She gave him a conspiratorial wink across the room.
• The documentary promoted conspiratorial claims without solid evidence.
• They exchanged conspiratorial glances before leaving the room together.