NOUN (2)

1. animal tissue that constitutes the essential part of an organ as contrasted with e.g. connective tissue and blood vessels;

2. the primary tissue of higher plants composed of thin-walled cells that remain capable of cell division even when mature; constitutes the greater part of leaves, roots, the pulp of fruits, and the pith of stems;

The Collaborative International Dictionary of English v.0.48:

parenchyma \pa*ren"chy*ma\ (p[.a]*r[e^][ng]"k[i^]*m[.a]), n.
   [NL., from Gr. pare`gchyma, fr. paregchei^n to pour in
   beside; para` beside + 'en in + chei^n to pour: cf. F.
   parenchyme.] (Biol.)
   The soft cellular substance of the tissues of plants and
   animals, like the pulp of leaves, the soft tissue of glands,
   and the like.
   [1913 Webster]

WordNet (r) 3.0 (2006):

parenchyma
    n 1: animal tissue that constitutes the essential part of an
         organ as contrasted with e.g. connective tissue and blood
         vessels
    2: the primary tissue of higher plants composed of thin-walled
       cells that remain capable of cell division even when mature;
       constitutes the greater part of leaves, roots, the pulp of
       fruits, and the pith of stems