[eternalban]

My definition: Design is the process of giving 'form' to 'concept'.

The space of 'concept -> form' has many dimensions, with aethetics merely being a more contentious one. A set of 'principles for design' (or a school of design) takes a position on each dimension of this transitional space. (Constructibiliy is another dimension, for example. Cost is another. etc.)

It is interesting that OP noted the linguistic aspects of word design. A bit further East, linguistically "form" is distinguished from "image", with general notion of "drawing" rooted in the latter.