Symbiosis (noun)

1. A close association between two organisms of different species that is beneficial to both.
2. An interdependent relationship between people, organizations, or countries that is mutually beneficial.

Origin:

Late 19th century: modern latin, from greek summōbiōsis, from sumbioun "living together", from sun- "together" + bioun "to live".

Examples:

1. The symbiosis between the whale and the tiny organism that cleans its skin is a prime example of mutualism.
2. The symbiosis between the two companies has been beneficial for both parties.
3. The symbiotic relationship between the plant and its pollinators is essential for their survival.
4. The symbiotic relationship between the two countries has been a source of strength and stability.
5. The symbiosis between the bee and the flower is an example of a mutually beneficial relationship.