The word greensands is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 15
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (21 words)
angered, dangers, degases, derange, endears, enraged, enrages, ensears, ensnare, ganders, gardens, genders, grassed, greased, greases, grenade, redness, resands, resends, sanders, senders