fallowEnglishOxford American Thesaurusfallow adjective 1 fallow farmland: uncultivated, unplowed, untilled, unplanted, unsown, unseeded, unused, undeveloped, dormant, resting, empty, bare, virgin; neglected, untended, unmaintained, unmanaged. ▷antonyms cultivated. 2 trading is set to emerge from a fallow period: inactive, dormant, quiet, slack, slow, slow-moving, flat, idle, inert, static, stagnant, depressed; barren, unproductive, unfruitful. ▷antonyms busy.