The word racecourses 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (48 words)
accruer, accrues, accurse, accuser, accuses, acerose, acerous, arouser, arouses, careers, carouse, causers, coarser, coercer, coerces, courser, courses, crasser, creaser, creases, crosser, cursers, cursors, erasers, erasure, rearose, recross, recures, recurse, recuses, reoccur, rescore, rescuer, rescues, saucers, scarcer, scarers, scorers, scourer, securer, secures, soarers, soccers, sources, succors, sucrase, sucrose, ureases