підпальцева виїмка (на руків'ї ножа тощо)
fingertip formation / finger-four formation / four finger formation
automatic pointing cutout system
cutout / cut-out
cutout cock
cutout control spring
cutout solenoid
ignition cutout
finger grip
finger groove
finger lever
finger tip control
finger-tip adjusting
have a finger on a nuclear trigger
hold a finger on a nuclear trigger