Saṃnāha

saṃnāha (T. go cha གོ་ཆ་; C. kǎijiǎ 鎧甲). Armour, mail, a coat of mail (made of iron or quilted cotton), etc.

The 84000 glossary states:

This is a protective clothing, made of closely interwoven strands, strapped around the body. In the Mahāyāna sūtras, it can be understood symbolically: the strands are the six perfections interlocking in a way that nothing can get through them. The strands bound together in the protective clothing may also be the net of interlocking beings occasioning a bodhisattva’s never-failing empathy.

The Digital Dictionary of Buddhism states:

Girding; esp. ancient armor that was made from metal or leather. (Skt. saṃnāha). 〔月燈三昧經 T 639.15.608c21〕 [Charles Muller; source(s): Gakken, Hirakawa, M-W]