brainiac

almanac, amberjack, anorak, antiblack, applejack, Arawak, Aurillac, back-to-back, bivouac, black-on-black, bric-a-brac, Cadillac, camelback, canvasback, cardiac, carryback, celiac, cornerback, Cousin Jack, crackerjack, cul-de-sac, diamondback, fiddleback, Gay-Lussac, gunnysack, hackmatack, haversack, high-low-jack, huckaback, hydrocrack, iliac, ipecac, Kodiak, ladder-back, leatherback, lumberjack, maniac, medevac, Merrimack, mommy track, multipack, nunatak, Nunivak, off-the-rack, paperback, Pasternak, piggyback, quarterback, razorback, retropack, running back, sandarac, Sarawak, silverback, single-track, snapper-back, steeplejack, stickleback, Syriac, tamarack, theriac, tokamak, turtleback, umiak, Unimak, zodiac