a pin bent back on itself to form a spring, with a guard to cover the point.
safe•ty-pinPronunciation: (sāf'tē-pin"), [key]
—v.t., -pinned, -pin•ning.
to secure or affix with a safety pin: to safety-pin a child's mittens to his coat sleeve.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.