Wiktionary
a. Extremely smooth (in any sense). adv. Extremely smooth (in any sense).
Usage examples of "smooth as silk".
Her hands seemed bloated, and clumsy, the nails broken off raggedly and rinded with black half -moons of dirt, and the harsh canvas of the ammunition belts between her fingers felt smooth as silk, the brass cartridge cases cool, so that she felt like pressing them to her dried cracked lips.
She sincerely hoped Colt had managed to get Liz away from the cabin, but either way, it looked like it was going to go down as smooth as silk.
The Pontiac's body looked like hell, but that motor ran smooth as silk.
But then he answered, in a voice as smooth as silk, ``It is what I came to do.
It ran smooth as silk on the rails, swaying gently back and forth in the way he had always loved since he was a boy.
Her voice was smooth as silk, with just the right touch of sympathy.