the.com/spec

means A written description of what something should look like or do before it's built — a specification, often used loosely for anything from a detailed blueprint to a vague wishlist.

from Simply short for 'specification,' which traces back to Latin 'specificare' — to name or identify specifically, from 'species' (kind, appearance) plus 'facere' (to make). The clipped form 'spec' shows up in engineering and trade talk, the kind of word-shortening that happens whenever busy people say something often enough to wear the edges off it.