The word isothermal 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: 16
Highest Scoring Words With Friends™ Play In The Letters isothermal
:
Seven Letter Word Alert: (57 words)
airhole, armhole, armlets, atheism, atomise, earshot, estriol, halites, halters, hamlets, hamster, harlots, hastier, hermits, heroism, holiest, holster, homiest, hostile, hostler, isolate, lathers, loamier, loather, loathes, loiters, maestro, mailers, maltier, maltose, marlite, mishear, mistral, moister, morales, mortals, mortise, mothers, motlier, rathole, realism, realist, remails, retails, saltier, shalier, slather, slatier, slither, smartie, smother, stromal, tailors, thermal, thermos, toilers, tramels