Chapter Three Lexicon morphology (2)The common factor underlying a set of forms: a word is th he common factor underlying the set of forms which are plainly variants of the same unit. such as walk. walks walking, walked. The underlying unit is often referred to as a lexeme, which is a unit of vocabulary, an item listed in a dictionary (a lexical item.(隐含于一组词形中的共同因素)(2) The common factor underlying a set of forms: a word is the common factor underlying the set of forms which are plainly variants of the same unit, such as walk, walks, walking, walked. The underlying unit is often referred to as a lexeme, which is a unit of vocabulary, an item listed in a dictionary (a lexical item).（隐含于一组词形中的共同因素) Chapter Three Lexicon & Morphology