Troughlike refers to something that resembles a trough, a long and narrow container that is usually used to hold food or water for animals. The antonyms of troughlike are different based on the context of usage. For instance, if troughlike is used to describe a shape, the antonyms could be spherical, cubical, or cylindrical. If it is meant to describe the texture, antonyms could include smooth, sleek, or polished. On the other hand, if troughlike is used to describe someone's mood or emotions, antonyms could include joyful, elated, or ecstatic. In conclusion, the antonyms of troughlike vary based on the context of usage.