Synonyms for Thoroughgoing (same or very similar meaning)
WordNet sense 1 (without qualification; used informally as (often pejorative) intensifiers):
arrant, consummate, everlasting, gross, perfect, pure, stark, unadulterated, utter, double-dyed, sodding, staring, consummate, perfectWordNet sense 2 (not diminished or moderated in intensity or severity; sometimes used as an intensifier):
unmitigatedWordNet sense 3 (very thorough; exhaustively complete):
exhaustive, thoroughWordNet sense 4 (having every necessary or normal part or component or step):
completeFrom the ODE community, based on WordNetadd/edit