A safety pin is a bent metal pin used for fastening things together. The point of the pin has a cover so that when the pin is closed it cannot hurt anyone.
...trousers which were held together with safety pins.
safety pin in British English
noun
1.
a spring wire clasp with a covering catch, made so as to shield the point when closed and to prevent accidental unfastening
2. another word for pin (sense 9)
safety pin in American English
a pin bent back on itself so as to form a spring, and having the point covered and held with a guard
Not only was she holding her jeans together with safety pins, she didn't have a winter coat that fit around her expanding figure.
Christianity Today (2000)
In other languages
safety pin
British English: safety pin /ˈseɪftɪ pɪn/ NOUN
A safety pin is a bent metal pin used for fastening things together. The point of the pin has a cover so that when the pin is closed it cannot hurt anyone.
...trousers which were held together with safety pins.