Eucalyptus approximans is a slender mallee that sometimes grows to a height of and has smooth white or grey bark. Young plants and
coppice regrowth have shiny green, linear to narrow lance-shaped leaves long and wide. They are a different shade of green on either side. Adult leaves are linear to lance-shaped or curved, long and wide on a
petiole long. They are the same glossy green on both sides. The flower buds are usually arranged in groups of seven, the groups on a
peduncle long and the individual flowers a
pedicel long. The mature buds are club-shaped, long and wide with a rounded to flattened
operculum. Flowering occurs between March and June and the flowers are white. The fruit is a cylindrical to cup-shaped
capsule long and wide on a pedicel up to long. ==Taxonomy and naming==