Definition of "Smoothness" :

noun: the quality of being free from errors or interruptions

"The five-speed manual gearbox is smoothness personified."

noun: the quality of having a level and even surface

"The water was a glassy smoothness."

noun: the quality of being bland and gracious or ingratiating in manner

noun: a texture without roughness; smooth to the touch

"Admiring the slim smoothness of her thighs."

noun: powerful and effective language

"His oily smoothness concealed his guilt from the police."