subtribe

noun

1. A tribe making up part of a larger tribe.

   “This leaves for consideration of this group of small tribes, or subtribes, so far as mapped by the writer quoted, the Teule, Cazcan, and Tecuexe.”

2. A taxonomic category ranking below tribe.

   “The tempo of evolution in South American hamsters was very rapid – in the course of the Pliocene and Anthropocene 40 genera were formed here, at which time a series of them attained the level of tribe and subtribe (Oxymycteri, Phyllotiini, Ichthyomyini).”

   “Brieger and his associates first divide the subtribe Epidendrinae […] into what could be called series, distinguishing four such series in the subtribe.”