1
general::
Diverge, subdivide, as in It's the house on the left, just after the road branches off, or English and Dutch branched off from an older parent language, West Germanic. This term alludes to a tree's growth pattern, in which branches grow in separate directions from the main trunk. [Second half of 1800s] Also see BRANCH OUT.
American Heritage Idioms
2
general::
Phrase(s): branch off (from something)
to separate off from something; to divide away from something. • A small stream branched off from the main channel. • An irrigation ditch branched off here and there.
McGrawhill's American Idioms And Phrasal Verbs