verb
delineate
dih-LIN-ee-ayt/dɪˈlɪnieɪt/
To represent something by clearly tracing its features.
A landscaper delineates a garden bed with a white marking line.

Etymology
The pieces convey marking something out fully in lines. This literal outlining developed into pictorial representation and then description in words, where the outline makes a subject's features or limits clear.
In context
I saw stones that look like they were trying to delineate the stream I take it those stones that were delineating the stream somebody put them there
More examples
- The report delineates the main causes of the shortage.
- Dotted lines delineate the property boundaries on this map.
- The agreement clearly delineates each partner's responsibilities.
Forms
delineate · delineates · delineated · delineating
delineation noun — A clear description or marking of boundaries.