The word radiometer 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: 14
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (33 words)
admirer, armoire, armored, demerit, dimeter, dreamer, emirate, etaerio, married, meatier, mediate, merited, mirador, mitered, miterer, readier, readmit, rearmed, redream, remated, remoter, retimed, retimer, retired, retrade, retread, retried, tardier, tarried, tearier, tireder, treader, trireme