The Collaborative International Dictionary of English v.0.48:

gypsyweed \gypsyweed\ n.
   A common hairy European perennial (Veronica officinalis)
   with pale blue or lilac flowers in axillary racemes.

   Syn: common speedwell, Veronica officinalis.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

gypsyweed
    n 1: common hairy European perennial with pale blue or lilac
         flowers in axillary racemes [syn: common speedwell,
         gypsyweed, Veronica officinalis]