I always wondered about this, so I decided to make sure everybody knew how use these words right.
systematic
1
: relating to or consisting of a system
2
: presented or formulated as a coherent body of ideas or principles
systematic thought
3
a
: methodical in procedure or plan
a systematic approach
a systematic scholar
b
: marked by thoroughness and regularity
systematic efforts
4
: of, relating to, or concerned with classification
specifically : TAXONOMIC
systemic
: of, relating to, or common to a system: such as
a
: affecting the body generally
systemic diseases
b
: supplying those parts of the body that receive blood through the aorta rather than through the pulmonary artery
c
: of, relating to, or being a pesticide that as used is harmless to the plant or higher animal but when absorbed into its sap or bloodstream makes the entire organism toxic to pests (such as an insect or fungus)
d
: fundamental to a predominant social, economic, or political practice
systemic poverty
So now you can keep them systematically straight.