The word respiratory 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
Seven Letter Word Alert: (46 words)
airport, artsier, aspirer, isotype, opiates, parrots, parties, pastier, pirates, porters, portray, praetor, praiser, praters, prayers, presort, prorate, pyrites, raptors, raspier, repairs, reports, reprays, reroast, respray, restrap, retraps, rioters, roarers, roaster, roister, ropiest, seaport, soapier, sorrier, sprayer, stirrer, strayer, striper, stripey, tarrier, tarries, terroir, terrors, topiary, traipse