safety plug
/ˈseɪftɪ plʌɡ/noun
1A plug or stopper which allows the contents of a container to be quickly and automatically released if the temperature becomes too high or the pressure too great; specifically one made of fusible metal, which melts when the contents become too hot, typically used in a boiler.
2A piece of plastic in the shape of an electrical plug which is used to cover a socket and protect against accidental electrocution (especially of young children).
Origin
Early 19th century. From safety + plug.
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- threepenny bit
- three-phase
- three-piece
- three-ply
- three-pointer
- three-point landing
- three-point turn
- three-pronged
- three-quarter
- three quarters
- threequel
- three-ring circus
- threescore
- three-sided
- Three Sisters
- threesome
- three-star
- Three Stooges
- three strikes
- three-way
- three-wheeler
- Three Wise Men
- thremmatology
- threnodial