Connascency at English => English (Websters 1913) Of Explained:
Connascence \Con*nas"cence\, Connascency \Con*nas"cen*cy\, n.
[L. con- + nascentia birth, fr. nascens, p. pr. of nasci to
1. The common birth of two or more at the same tome;
production of two or more together. --Johnson.
2. That which is born or produced with another.
3. The act of growing together. [Obs.] --Wiseman.