The term "root tubercle" is commonly used in botany to refer to the swollen area on the root system where the root and stem meet. Synonyms for "root tubercle" include "root nodule", "root bump", "root bulb", and "root protuberance". These terms all describe the same anatomical feature, which functions as a site for nitrogen fixation by bacteria or endomycorrhizal associations. While "root tubercle" is the most widely recognized term, the use of these synonyms provides alternatives that can be employed to describe this important structure in plant root systems.