Systematic is the more common word; it most often describes something that is done according to a system or method. Systemic describes what relates to or affects an entire system, be that system …

SYSTEMATIC definition: having, showing, or involving a system, method, or plan. See examples of systematic used in a sentence.

SYSTEMATIC definition: 1. according to an agreed set of methods or organized plan: 2. according to an agreed set of…. Learn more.

Use the adjective systematic to describe things that are orderly and efficient. The Latin root of systematic is systema, an arrangement or system. Think about a multi-step process that you have …

done according to a system or plan, in a complete, efficient or determined way. The prisoner was subjected to systematic torture. Definition of systematic adjective in Oxford Advanced Learner's …

1. Characterized by, based on, or constituting a system: systematic thought. 2. Working or done in a step-by-step manner; methodical: a systematic worker; a systematic approach.

Something that is done in a systematic way is done according to a fixed plan, in a thorough and efficient way. They began a systematic search.

Systematic definition: Working or done in a step-by-step manner; methodical.

There are 11 meanings listed in OED's entry for the word systematic, four of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

In simplest terms, something described as systematic uses or follows a system, while something described as systemic is part of, or is embedded in, the system itself.