Source : Webster's Revised Unabridged Dictionary (1913)

Obmutescence \Ob`mu*tes"cence\ ([o^]b`m[-u]*t[e^]s"sens), n. [L.
   obmutescens, p. pr of obmutescere to become dumb; ob (see
   {Ob-}) + mutescere to grow dumb, fr. mutus dumb.]
   1. A becoming dumb; loss of speech. --Sir T. Browne.

   2. A keeping silent or mute. --Paley.