INVAGINATION
In*vag`i*na"tion, n. Etym: [L. pref. in- + vagina sheath.]
1. (Biol.)
Defn: The condition of an invaginated organ or part.
2. (Biol.)
Defn: One of the methods by which the various germinal layers of the ovum are differentiated.
Note: In embolic invagination, one half of the blastosphere is pushed in towards the other half, producing an embryonic form known as a gastrula. — In epibolic invagination, a phenomenon in the development of some invertebrate ova, the epiblast appears to grow over or around the hypoblast.
INVALESCENCE In`va*les"cence, n. Etym: [L. invalescens, p. pr. of invalescere to become strong. See 1st In-, and Convalesce.]
Defn: Strength; health. [Obs.]
INVALETUDINARY
In*val`e*tu"di*na*ry, a.
Defn: Wanting health; valetudinary. [R.]