Cottonseed rhymes with:
linseed, aniseed, appleseed, flaxseed, linseed, oilseed, rapeseed, airspeed, aniseed, appleseed, ashmead, centipede, certainteed, duckweed, fireweed, flaxseed, ganymede, goodspeed, highspeed, inbreed, krumwiede, linseed, lockheed, milkweed, nobody'd, nosebleed, oilseed, pitied, pokeweed, proofread, ragweed, rapeseed, rosemead, seaweed, siegfried, windspeed