noun
three-legged race
A race in which two people run together with their adjacent legs tied together.
運動会で二人三脚に出た。
I participated in the three-legged race at the sports day.
noun
close cooperation
Figurative use describing two parties (people, companies, etc.) working closely together toward a single goal, as if tied together like in a three-legged race.
両社は二人三脚で新製品を開発した。
The two companies developed the new product in close cooperation.