Meaning of expressivity

ex•pres•siv•i•ty

Pronunciation: (ek"spre-siv'i-tē), [key]
— n.
  1. the quality or state of being expressive.
  2. the degree to which a particular gene produces its effect in an organism. Cf. penetrance.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.