1 a (1) : having a continuous even surface (2) of a curve : being the representation of a function with a continuous first derivative (3) : having or being a short even coat of hair a smooth collie
-> compare rough, wirehaired b : being without hair c : glabrous a smooth leaf d : causing no resistance to sliding 2 : free from difficulties or impediments the smooth course of his life 3 : even and uninterrupted in flow or flight 4 : excessively and often artfully suave : ingratiating a smooth operator 5 a : serene, equable a smooth disposition b : amiable, courteous 6 a : not sharp or harsh a smooth sherry b : free from lumps