Source : Webster's Revised Unabridged Dictionary (1913)

Chickweed \Chick"weed`\ (-w[=e]d`), n. (Bot.)
   The name of several caryophyllaceous weeds, especially
   {Stellaria media}, the seeds and flower buds of which are a
   favorite food of small birds.

Source : WordNet®

chickweed
     n 1: any of various plants of the genus Stellaria
     2: any of various plants related to the common chickweed [syn:
        {mouse-ear chickweed}, {mouse eared chickweed}, {mouse ear},
         {clammy chickweed}]