The word knightliness 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: 23
Highest Scoring Words With Friends™ Play In The Letters knightliness
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Seven Letter Word Alert: (54 words)
english, enlight, enlists, ensigns, glisten, hinnies, hinting, hissing, ignites, ingests, inkiest, inkless, inkling, inlines, insight, kilning, kilting, kinesin, kinesis, kinless, kissing, knights, lengths, lensing, lighten, lignins, lignite, likings, linings, linking, linnets, listens, listing, nesting, nightie, sensing, shingle, shining, signets, silents, silkens, silting, singles, singlet, sinking, sinlike, sleighs, sleight, slights, tensing, tilings, tingles, tinkles, tinsels