1. the action of working with someone to produce or create something
2. traitorous cooperation with an enemy
Usage: historical; often refers to wartime

Examples

• The research project was a collaboration between three universities.
• Their collaboration on the album produced several hit songs.
• International collaboration is essential for addressing climate change.
• The software was developed through collaboration with industry experts.
• The artist's collaboration with the museum resulted in a stunning exhibition.
• During World War II, collaboration with occupying forces was considered treason.
• The successful collaboration between departments improved efficiency.