oleaginous

adj

Etymology: Borrowed from French oléagineux, borrowed from Medieval Latin oleāginōsus (“oily”), from olea (“the olive tree or its fruit”).

1. Oily, greasy.

   “[…] the use of Linseed-oyl, Tar, or such oleaginous Matter, tends much to their Preservation and Duration.”

   “Looking back, it seemed to me that a slight oleaginous mist was still hovering round the chair.”

2. Falsely or affectedly earnest; persuasively suave.

   “The oleaginous salesman convinced me to buy a more expensive car.”

   “Cruz was obviously analogizing Bernie Sanders to the Bolsheviks and Hillary Clinton to the Mensheviks. The oleaginous Texan is an erudite slyboots, but his history is off-kilter.”