1. [n]  cultivated for its shining oblong leaves and arching clusters of white flowers with shell-pink shading and crinkled yellow lip with variegated magenta stripes
2. [n]  showy perennial of marshlands of eastern and central North America having waxy lanceolate leaves and flower with lower part creamy white and upper parts pale pink to deep purple

SHELLFLOWER is a 11 letter word that starts with S.