1.
insulator — a material that does not conduct electricity (or heat) well; e.g., rubber, glass, or ceramic used to block current flow
A substance that does not readily allow the flow of electric current (and sometimes, by extension, of heat). Examples include rubber, glass, plastics, and ceramics. Used in physics and electrical engineering in contrast to 導体 ('conductor') and 半導体 ('semiconductor').
ゴムは絶縁体です。
Rubber is an insulator.
電線は絶縁体で覆われている。
Electrical wires are covered with an insulator.
ガラスやプラスチックは一般的に絶縁体として使われる。
Glass and plastic are generally used as insulators.
金属は電気を通すが、ゴムや陶器のような絶縁体は通さない。
Metals conduct electricity, but insulators such as rubber and ceramics do not.
Compound of 絶縁 ('insulation, cutting off [a connection]') and 体 ('body, substance'). Literally 'insulating substance.'
USAGE:
- A standard physics and electrical-engineering term for a material that blocks the flow of electricity.
- Appears in textbook discussions alongside 導体 ('conductor') and 半導体 ('semiconductor').
- By extension, sometimes used for heat insulators, but for thermal insulation the more specific term 断熱材 is usually preferred.
- The base word 絶縁 also has a figurative meaning of 'severing ties' between people, but 絶縁体 is limited to the physics/engineering sense.
COMMON COLLOCATIONS:
- 絶縁体で覆う: to cover with an insulator
- 絶縁体として使う: to use as an insulator
- 良い絶縁体: a good insulator
- 絶縁体の性質: properties of an insulator
SIMILAR WORDS:
- 導体: conductor — a material that conducts electricity well; the direct antonym.
- 半導体: semiconductor — a material with conductivity between that of a conductor and an insulator.
- 不導体: non-conductor — a near-synonym of 絶縁体; slightly older/literary.
- 断熱材: thermal insulation material — used specifically for heat insulation (e.g., in walls of houses).