Trophic things have something to do with food, eating, or nutrition. You're most likely to encounter this word in an Earth science or biology textbook, where you might read about trophic webs, or interconnected food chains.
Many important ideas in the study of ecology, or the science of how organisms relate to their environment and each other, have some connection to trophic subjects. One example is a "trophic cascade," an upset in the food chain that happens when large numbers of predators are removed. Trophic has a Greek root, trophe, "nourishment or food."