subtopic

[ suhb-top-ik, suhb-top- ]
/ ˈsʌbˌtɒp ɪk, sʌbˈtɒp- /

noun

a topic that is included within another topic.

Origin of subtopic

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019