The word "in sinuate" refers to something that is curving or winding. Antonyms to this word could include words like straight, linear, or direct. Another antonym that could be used is angular, which means having sharp corners or angles instead of curves. Another option could be rigid, meaning stiff and inflexible, rather than something that can bend and flow like an in sinuate line. Finally, the word disconnected could also serve as an antonym, as it implies a lack of flow or continuity, rather than the smooth curve suggested by in sinuate.