The word progenitors 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: 17
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (69 words)
egotrip, erosion, girners, goiters, goitres, gooiest, goopier, goosier, goriest, gripers, grister, gropers, ignores, ironers, isotope, norites, operons, options, orients, orogens, pigeons, pingers, pingoes, pointer, poorest, porters, porting, portion, postern, posting, potions, presort, printer, pronest, protein, protons, pterins, regions, regrips, repoint, reports, reprint, reroots, resting, ringers, rioters, roister, rooster, rooters, rooting, ropiest, snooper, snorter, sootier, sooting, sorting, sponger, sporing, sporont, stinger, stonier, stooper, storing, striper, toonies, torpors, torsion, triones, trooper