Convergence (?), Convergency (?) , n. [Cf. F. convergence.]
1. The condition or quality of converging; tendency to one point; the occurrence of two or more things coming together.
[1913 Webster]
2. (Math.) the approach of an infinite series to a finite limit.
Syn. -- convergency.
[WordNet 1.5]
3. a representation of common ground between theories or phenomena.
Syn. -- overlap, intersection.
[WordNet 1.5]
4. the act of converging (coming closer).
Syn. -- converging, convergency.
[WordNet 1.5]
5. (Biol.) a similarity of form or function in two or more organisms caused by evolutionary adaptations to a similarity in the environment, rather than to a common heredity.
[PJC]
The convergence or divergence of the rays falling on the pupil. Berkeley.
[1913 Webster]