معنی کلمه :‌ breech screw

A strong iron or steel plug screwed into the breech of a musket or other firearm, to close the bottom of the bore.

(a) A species of very large rat (Mus giganteus), found in India and Ceylon. It does much injury to rice fields and gardens. (b) A ratlike marsupial animal (genus Perameles) of several species, found in Australia and Tasmania.