stem: the central or basic part of a word, the part to which affixes can be attached. For instance the stem of "hands" is "hand". A stem can be either monomorphemic or polymorphemic; monomorphemic stems are often called roots. For instance in the word "unmistakably", "take" would be the monomorphemic stem or root, but we can also recognize as (polymorphemic) stems "mistake", "mistakable", and" unmistakable". Compare compound. [Spanish: raíz]