i only know trope in the scientific sense--which retains the meaning.. (to turn)
phototropism is what causes a sun flower to turn its head, and follow the sun..
(geotropism causes roots to respond to gravity, and dig into the earth--an imporant function of a rootlet of an emerging seedling) there a hundreds of 'trope/tropism' in biology.

Dr Bill, maybe the connection of turning sunflowers will help you remember trope's turning characteristics!


my other obsession