Definition of yessiree in English:

yessiree

Pronunciation /ˌjɛsəˈriː/

exclamation

(also yessirree)
informal US
  • Used to express emphatic affirmation: ‘yes indeed’. Occasionally more fully "yessiree bob", "yessiree bub". Compare no siree , "yessir".

Origin

Mid 19th century; earliest use found in Dollar Newspaper (Philadelphia). From yes + siree, variant of sorry.