english
1
general::
Phrase(s): butter someone up [and] butter up to someone to flatter someone; to treat someone especially nicely in hopes of receiving special favors. (See also spread something on thick; soft soap.) • A student tried to butter the teacher up. • She buttered up the teacher again.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Excessively praise or flatter someone, usually to gain a favor. For example, If you butter up Dad, he'll let you borrow the car. This term transfers the oily, unctuous quality of butter to lavish praise. [c. 1700]
American Heritage Idioms