An aglet (or aiglet) is a small plastic or metal covering used on the end of a shoelace, cord, or drawstring. An aglet keeps the fibers of the lace or cord from unraveling. Its firmness and narrow profile make it easier to hold and easier to feed through the eyelets, lugs, or other lacing guides.
First used in the 15th century, the word aglet (or aiglet) comes from Middle English, from Middle French aguillette, aiguillette, from Old French, diminutive of aguille, aiguille meaning needle, from Late Latin acicula, acucula meaning ornamental pin, a diminutive of Latin acus meaning needle or pin.
Aglets today are most often made of plastic but have also been made of metal, glass, and stone. Historically, many were highly ornamental and made of precious metals, such as silver. Before the invention of buttons, aglets were used on the ends of ribbons to fasten clothing together. Sometimes they were formed into small figures. Shakespeare called this type of figure an “aglet baby” in The Taming of the Shrew.
Source: Merriam-Webster.com, Wikipedia