cyl·in·der 
/ˈsɪləndɚ/ noun
plural cyl·in·ders /ˈsɪləndɚ/ noun [count] 1 : a shape that has straight sides and two circular ends — see picture at geometry 2 : something that is shaped like a cylinder: such as a : a tube in which a piston of an engine moves
▪ a four-cylinder engine — see picture at engine
b : the part of a gun that turns and that holds the bullets
▪ the cylinder of a revolver
▪ a four-cylinder engine — see picture at engine
b : the part of a gun that turns and that holds the bullets
▪ the cylinder of a revolver
on all cylinders
informal : with the greatest possible amount of effort, power, or speed : at full capacity or speed
▪ The economy is running on all cylinders. ▪ The team didn't seem to be firing/hitting on all cylinders.
▪ The economy is running on all cylinders. ▪ The team didn't seem to be firing/hitting on all cylinders.
