1: Synergistically similar connection between two partners that make each partner greater that their individual or independent whole.
2: Mutually advantageous conjunction or compatibility of distinct relationship participants or elements (as resources or efforts) that independently are greater than the sum of each before the connection.
3: A relationship that shares inspiration so both can reach their greatest potential.

An independent event whose value becomes greater when acted upon by a similar (though distinct) event, but whose value is invariant when held mutually exclusive from said event.