Defining several terms Morphology,Morpheme,Morph Allomorph: Morphology. the branch of linguistics that studies the internal structure of words and the rules by which words are formed. Morpheme(语素/词素/形位)： morph-:form,-eme:the smallest unit or class of. --the smallest meaningful linguistic unit of language,not divisible or analyzable into smaller forms.Defining several terms Morphology, Morpheme, Morph & Allomorph: Morphology: the branch of linguistics that studies the internal structure of words and the rules by which words are formed. Morpheme (语素 / 词素 / 形位): morph-: form, -eme: the smallest unit or class of. --the smallest meaningful linguistic unit of language, not divisible or analyzable into smaller forms