The Collaborative International Dictionary of English v.0.48:

Ingress \In"gress\, n. [L. ingressus, fr. ingredi. See
   Ingredient.]
   [1913 Webster]
   1. The act of entering; entrance; as, the ingress of air into
      the lungs.
      [1913 Webster]

   2. Power or liberty of entrance or access; means of entering;
      as, all ingress was prohibited.
      [1913 Webster]

   3. (Astron.) The entrance of the moon into the shadow of the
      earth in eclipses, the sun's entrance into a sign, etc.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ingress \In"gress\, v. i.
   To go in; to enter. [R.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

ingress
    n 1: (astronomy) the disappearance of a celestial body prior to
         an eclipse [syn: ingress, immersion] [ant: egress,
         emersion]
    2: the act of entering; "she made a grand entrance" [syn:
       entrance, entering, entry, ingress, incoming]