The word vivisectionists 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: 27
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (32 words)
cession, consist, contest, cosiest, cosines, covines, eosinic, iciness, iconist, incests, incises, incites, inosite, insects, insists, invects, invests, invites, invoice, ionises, nosiest, notices, notists, novices, oecists, osseins, section, session, stetson, tiniest, tocsins, visions