systematics
noun
sys·tem·at·ics ˌsi-stə-ˈma-tiks 
plural in form but singular in construction
1
: the science of classification
2
a
: a system of classification
b
: the classification and study of organisms with regard to their natural relationships : taxonomy
Example Sentences
Recent Examples on the Web There are errors that are well-quantified from three sources: statistics, systematics, and external input uncertainties; all of them are far too insignificant to explain this discrepancy. 
Ethan Siegel, Forbes, 12 Mar. 2021 More than half of the top 100 journals in ecology, evolution, behavior and systematics mention or require the permanent archival of DNA sequences. Popular Science, 18 Dec. 2020
Ethan Siegel, Forbes, 12 Mar. 2021 More than half of the top 100 journals in ecology, evolution, behavior and systematics mention or require the permanent archival of DNA sequences. Popular Science, 18 Dec. 2020 Word History
First Known Use
1879, in the meaning defined at sense 1
Medical Definition
systematics
noun, plural in form but singular in construction
sys·tem·at·ics ˌsis-tə-ˈmat-iks
1
: the science of classification
2
a
: a system of classification
b
: the classification and study of organisms with regard to their natural relationships : taxonomy