IPA: /ˌsʌbˈmjuːsəl/
KK: /sʌbˈmjuːsəl/
Located beneath the mucous membrane in the body.
The doctor explained that the submucosal layer plays an important role in digestion.
Submucosal → It is formed from "sub-" (meaning under) and "mucosa" (from Latin "mucosa", meaning mucous membrane) and the suffix "-al" (meaning pertaining to). The word "submucosal" refers to something that is pertaining to or located under the mucous membrane.
Think of something that is 'under' ('sub-') the 'mucous membrane' ('mucosa') — that's what submucosal means.