four-groove
four-gun
four-high
Fourier
four-lane
four-level
four-line
four-lined
four-link
four-lipped
  four-lug
four-piece
four-pole
four-quaternary
four-seater
four-spring
four-square
four-stage
four-stream
four-stroke
four-terminal

    four-lug bolt

    затвор с четырьмя боевыми выступами