Agnate, accompanying, and affiliated are all synonyms for related. Unconnected, separate, and unrelated are antonyms of related. And here are 26 another word for related.
Accompanying, affiliated, agnate, akin, allied, analogous, associated, comparable, concomitant, connected, consanguineous, correlated, corresponding, coupled, equivalent, homologous, incidental, interconnected, kin, kindred, linked, of the same blood, of the same family, parallel, and cognate are all synonyms for related.
The topics are closely related, surprisingly.
They discussed related issues extensively today.
Her research is related to psychology.
Many stories are related in history.