WordNet (r) 3.0 (2006):
snow-in-summer n 1: annual spurge of western United States having showy white- bracted flower clusters and very poisonous milk [syn: snow-on-the-mountain, snow-in-summer, ghost weed, Euphorbia marginata] 2: chickweed with hairy silver-grey leaves and rather large white flowers [syn: snow-in-summer, love-in-a-mist, Cerastium tomentosum]