The word haemagglutinate 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: 27
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (81 words)
agamete, agatine, agitate, agnatha, ailment, aliment, alumina, alumnae, amanita, amentia, anaemia, animate, athlete, augment, elating, elegant, eluting, emanate, emulant, emulate, enlight, entitle, galette, ganglia, gateman, gatemen, gelatin, geminal, genital, gentile, getting, gingham, glueing, gmelina, gutting, halting, hatting, haulage, hauling, healing, heating, heeling, hemline, hutting, laminae, lathing, legumin, letting, lighten, lineage, lineate, magenta, magnate, maleate, malting, manatee, matinee, matting, mauling, meeting, megahit, melange, melting, methane, mileage, mintage, mutagen, nametag, netmail, nutmeal, nutmeat, tagline, tailgun, tauting, teaming, teatime, teeming, tentage, thalami, tighten, unagile