Latin designare, de- (“completely”) + signare (“to mark with a sign”, from signum, “sign”). It literally meant to trace, mark, indicate with precise signs, but also to destine, plan, preordain.
Old French: designier / desiner / desseigner / desinner (variant medieval spellings). It meant to draw, indicate, depict, intend a project. From this derives the word “desin” or “desinn”, an archaic form (now obsolete) that indicated the stroke or drawing in both the figurative and material sense — the act of marking a form.