The word slenderising 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™ Plays In The Letters slenderising
:
Seven Letter Word Alert: (78 words)
deleing, deniers, designs, desires, diesels, digress, dingier, dingies, dinners, dissing, eldress, eleidin, eliding, endings, endless, engined, engines, ensigns, gelders, genders, genesis, gilders, girdles, girlies, girnels, gliders, greisen, grinned, ingress, inlines, insider, insides, ledgers, leering, legends, lenders, lending, lensing, lignins, lindens, lingers, linings, linseed, needing, redline, redness, reeling, regilds, reigned, reining, relined, relines, rending, resends, resides, resigns, ridings, rinsing, risings, sedgier, seeding, senders, sending, sensing, sidings, sidlers, sidling, signees, signers, singers, singled, singles, sinners, sledges, slender, sliders, sliding, slinger