The word histological 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: 21
Highest Scoring Words With Friends™ Play In The Letters histological
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Seven Letter Word Alert: (21 words)
alcohol, alights, cahoots, colitis, coltish, galoots, gasohol, goatish, gotchas, gothics, illogic, ischial, italics, logical, oligist, ooliths, oolitic, shallot, solicit, stoical, tallish