The word greaseballs 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (30 words)
abasers, abrases, ageless, algebra, alleger, alleges, bagless, beagles, blesser, braless, earless, garbles, greases, laagers, labeler, largess, leasers, legless, rebales, rebases, rebells, rebless, relabel, resales, reseals, resells, salable, seabags, sealers, sellers