The word "stem" can refer to several concepts depending on the context. Generally, it is used to denote the main body of a plant, which supports leaves, flowers, or fruits. In a broader sense, "stem" can also mean to originate from or be part of a source, as in the phrase "to stem from." Additionally, in mathematics, "stem" can refer to the main part of a word, particularly in linguistics.
The word "stem" comes from the Old English "stem," which meant "trunk" or "main part." This can be traced back further to Proto-Germanic roots and ultimately to Proto-Indo-European origins, where it was associated with the idea of standing upright or being stable.