A shirt with a collar that can be worn either open or closed

To handle matters impartially and avoid extremes; to follow the golden mean. From the [[中庸|中庸|zhong1 yong1]], meaning to hold both ends and apply the middle course for the people.

to use one thing for two purposes or to achieve two goals with a single effort

Capable of operating on both land and water; used to describe vehicles or equipment.