Milliylik-millat ko'zgusi
Kalit (ochqich) – 1) qulfni ochish va qulflash uchun maxsus shakldagi metall tayoqcha; 2) gaykani bo’shatish yoki mahkamlash, biror narsani yuritish, tiqin ochish uchun asbob. Masalan: jo’mrak ochqichi, ikki dastakli quvur kaliti va hokazolar.