This is an abbreviation for SNOMED CT description.
SNOMED CT description
An association between a human-readable phrase (term) and a particular SNOMED CT concept.
Notes
Each description is represented by a separate row in the Description File.
Each description has a unique identifier and connects a concept with a term of a specified description type. All concepts have descriptions with description types fully specified name and synonym. Other description type can be defined and may be applied to some concepts.
