full-blown

the compound 'full-blown' originates from the literal description of a flower that has opened completely, with 'blown' being an archaic past participle of 'blow' used in the sense of 'bloomed' or 'expanded'. this botanical imagery was metaphorically extended by the 17th century to describe any situation, condition, or disease that has reached its most complete or advanced stage. the logic of the term hinges on the visual metaphor of a bud achieving its final, fully expanded form, thereby conveying the sense of something being entirely developed or manifest.

Structure: full (complete) + blown (expanded) full (from old english 'full', meaning 'complete, entire'), blown (past participle of 'blow', from old english 'blāwan', meaning 'to move air, to bloom')