The word viscoelastic 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: 23
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (55 words)
accites, accosts, actives, alcoves, alecost, aloetic, ascetic, ascites, cacolet, calcite, calicos, castile, castles, celosia, ciliate, ciscoes, classic, clastic, clitics, closest, closets, coalise, coalite, coeliac, colitis, cosiest, elastic, elicits, estival, icicles, ilvaite, iolites, isolate, italics, laciest, lactose, laicise, liaises, locates, octaves, oecists, oiliest, ossicle, sciatic, silicas, socials, solaces, solicit, stoical, vesical, violate, violets, violist, vocalic, voltaic