Definition of underlever in English:

underlever

noun

  • A lever behind the trigger guard on a rifle.

    [as modifier] ‘bolt action with underlever cocking’
    • ‘The Model 46 has an underlever cocking system, flip-up loading port, automatic safety, adjustable rear sight, adjustable trigger, extended scope rail, and a rifled barrel.’

Pronunciation:

underlever

/ˈʌndəliːvə/