Open English Wordnet
Nouns
(n)branch, subdivision, arma division of some larger or more complex organization“a branch of Congress”, “botany is a branch of biology”, “the Germanic branch of Indo-European languages”
(n)section, subdivisiona self-contained part of a larger composition (written or musical)“he always turns first to the business section”, “the history of this work is discussed in the next section”
(n)subsection, subdivisiona section of a section; a part of a part; i.e., a part of something already divided