Real Dictionary

taxonomy
a horizontal datum line or plane [...]
a number of persons or things considered as a collective unit [...]
the act of putting together or making up by combining parts or ingredients [...]
the branch of biology concerned with the classification of organisms into groups based on similarities of structure, origin, etc [...]
the first position in a place-value counting system, representing a single-digit number [...]
variable noun: Taxonomy is the process of naming and classifying things such as animals and plants into groups within a larger system, according to their similarities and differences.

taxonomy in American English
the science of classification; laws and principles covering the classifying of objects
noun: the science or technique of classification

taxonomy in British English
noun: the branch of biology concerned with the classification of organisms into groups based on similarities of structure, origin, etc