Tetramorium lanuginosum is a small ant with a reddish head, mesosoma and waist contrasting with a dark gaster, and a dense pelt of long white pilosity. This species has a monomorphic worker caste with 12-segmented antennae, three-segmented antennal club, antennal scrobes, short antennal scapes that do not surpass the posterior margin of the head, a gradually sloped mesosoma, and strong propodeal spines. Like all myrmicines, T. lanuginosum has two waist segments and a gaster armed with a stinger. Tetramorium lanuginosum (formerly known as Trigliphothrix striatidens) is widely distributed across the Pacific and other tropical regions. It is most often encountered in forest leaf litter. The species is not known to cause significant damage to ecological or agricultural systems.