Con*nas"cence (?), Con*nas"cen*cy (?), n. [L. con- + nascentia birth, fr. nascens, p.pr. of nasci to be born.]
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.
© Webster 1913.