Workable if making a design essentially obvious (7)
I believe the answer is:
visible
'obvious' is the definition.
(similar in meaning)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for visible that I've seen before include "Showing up" , "Able to be seen" , "Apparent" , "Obvious to the eye" , "Perceptible by the eye" .)