The word tardiness 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: 11
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (35 words)
antsier, aridest, astride, destain, detains, detrain, disrate, dissent, inserts, instars, instead, nastier, resands, restain, retains, retinas, sainted, sanders, sandier, sardine, satires, seitans, sestina, sinters, snidest, stained, stainer, stander, strains, strands, strides, tinders, tirades, tradein, trained