three-arm
three-armed
three-aspect
three-axis
three-banger
three-bar
three-barrelled
three-base
three-bath
three-bay
  three-beam
three-bit
three-block
three-body
three-box
three-car
three-cell
three-center
three-centered
three-circuit
three-coat

    three-beam grating

    решётка с тремя дифракционными порядками