Antidesma venosum is an evergreen to semi-deciduous tree or shrub from 0.55 up to 15 m tall, with a dense, roundish crown. Old stems are buff-grey in shade and pale grey in sunny habitats. Middle age branchlets are glabrous and brown to grey-brown with scattered pale grey lenticels. New twigs are very hairy, green becoming pale brown with age. Bark is channeled longitudinally, soft and very hairy, scattered with pale grey lenticels.

Leaves simple, alternate, more or less spirally arranged, with rounded or bluntly pointed tips, about 150 mm long and 70 mm broad. Leaf blade leathery, dark glossy green, lower surface is covered with rusty hairs and has prominent venation looping along margin, paler green below with midrib raised and margins smooth. Leaf stalk hairy, up to 6 mm long.

Flowers are small and unpleasantly scented, but showy and distinctive. Male flowers are produced in long, thin catkins which are found at the ends of newly grown twigs. Female flowers are produced in thin but shorter catkins at the ends of twigs. Flowering time is in early summer, from October to January. Fruits are very small, almost oval, ±10 mm in length and 8 mm in diameter, with a soft exocarp and fleshy, edible mesocarp, pale yellow to blood-red, turning black when ripe. Fruiting time is in late summer to autumn, from January to May.