Note:
A branch unit from which 
linear chains emanate may be termed an f-functional branch unit, e.g. five-functional branch unit. Alternatively, the terms trifunctional, tetrafunctional, pentafunctional, etc. may be used, e.g. pentafunctional branch unit.
linear chains emanate may be termed an f-functional branch unit, e.g. five-functional branch unit. Alternatively, the terms trifunctional, tetrafunctional, pentafunctional, etc. may be used, e.g. pentafunctional branch unit.Source:
PAC, 1996, 68, 2287
(Glossary of basic terms in polymer science (IUPAC Recommendations 1996))
on page 2297