Negative tropisms refer to the movement of an organism away from a stimulus. In plants, this can be seen as leaves turning away from light or roots growing away from toxic substances. There are several synonyms for negative tropisms including: negative geotropism, negative phototropism, and negative chemotropism. Negative geotropism refers to the movement of an organism away from gravity, like when roots grow horizontally instead of vertically. Negative phototropism is the movement away from light, and negative chemotropism is the movement away from a chemical stimulus. These synonyms help to describe the different ways in which organisms respond to negative stimuli in their environment.