The word 'sulcus' is a direct borrowing from Latin, where it meant "furrow, trench, or wrinkle." The Latin term itself is of uncertain deeper origin, though it may be related to the verb sulcare, meaning "to plow or to furrow." This literal agricultural sense was adopted into anatomical and biological terminology in New Latin to describe any long, narrow groove, such as those found on the surface of the brain or in other bodily tissues. The journey from a term for a plowed trench in a field to a precise descriptor for a cerebral groove exemplifies the common practice of repurposing concrete, everyday vocabulary for specialized scientific description.

The word is a simplex loanword from Latin. It is not productively segmented using modern English spelling substrings.