From Latin phylum, from Ancient Greek φῦλον (phulon, “tribe, race”).
phylum (plural phyla or phylums)
- (biology, taxonomy) A rank in the classification of organisms, below kingdom and above class; also called a division, especially in describing plants; a taxon at that rank
- Mammals belong to the phylum Chordata.
- (linguistics) A large division of possibly related languages, or a major language family which is not subordinate to another.
(biology, taxonomy) A rank in the classification of organisms, below kingdom and above class
Derived terms 
phylum (genitive phylī); n, second declension