noun
Refers to an electrical insulator, typically a ceramic or composite device used to support and separate electrical conductors.
電柱に白いがい子が並んでいる。
White insulators are lined up on the utility pole.
高圧線のがい子は定期的に点検が必要だ。
Insulators on high-voltage lines need regular inspection.
Old-form kanji spelling using 礙 (kyūjitai of 碍); rarely encountered.
絶縁体 is a general term for any insulating material, while がい子 specifically refers to the physical device used in electrical power systems.
Compound of 碍 (gai, 'obstruction' or 'hindrance') and 子 (shi, 'small thing' or 'element'). The kanji 碍 is a simplified form of 礙, meaning 'to obstruct'. The word was coined in the late 19th or early 20th century as a technical term for electrical insulators.