The Collaborative International Dictionary of English v.0.48:

Mallow \Mal"low\, Mallows \Mal"lows\, n. [OE. malwe, AS. mealwe,
   fr. L. malva, akin to Gr. mala`chh; cf. mala`ssein to soften,
   malako`s soft. Named either from its softening or relaxing
   properties, or from its soft downy leaves. Cf. Mauve,
   Malachite.] (Bot.)
   A genus of plants (Malva) having mucilaginous qualities.
   See Malvaceous.
   [1913 Webster]

   Note: The flowers of the common mallow (Malva sylvestris)
         are used in medicine. The dwarf mallow (Malva
         rotundifolia) is a common weed, and its flattened,
         dick-shaped fruits are called cheeses by children. Tree
         mallow (Malva Mauritiana and Lavatera arborea),
         musk mallow (Malva moschata), rose mallow or
         hollyhock, and curled mallow (Malva crispa), are less
         commonly seen.
         [1913 Webster]

   Indian mallow. See Abutilon.

   Jew's mallow, a plant (Corchorus olitorius) used as a pot
      herb by the Jews of Egypt and Syria.

   Marsh mallow. See under Marsh.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mallow
    n 1: any of various plants of the family Malvaceae