WordNet sense 1 (poisonous perennial Old World vine having violet flowers and oval coral-red berries; widespread weed in North America):

bittersweet nightshade, climbing nightshade, poisonous nightshade, Solanum dulcamara, woody nightshade, deadly nightshade

WordNet sense 2 (twining shrub of North America having yellow capsules enclosing scarlet seeds):

waxwork, American bittersweet, Celastrus scandens, climbing bittersweet, false bittersweet, shrubby bittersweet, staff vine

WordNet sense 3 (having a taste that is a mixture of bitterness and sweetness):

semisweet

WordNet sense 4 (pleasing to the sense of taste):

tasty

WordNet sense 5 (experiencing or showing sorrow or unhappiness):

sad