Full-blown means having all the characteristics of a particular type of thing or person. Before becoming a full-blown director, he worked as the film editor on Citizen Kane. having all the qualities of something that is at its most complete or advanced stage (FULL + blown, past participle of blow , from blowan)
[ 'ful also 'f&l ] (adjective.) before 12th century. Middle English, from Old English; akin to Old High German fol full, Latin plenus full, plEre to fill, Greek plErEs full, plEthein to be full.