Do you know ghouls from goblins and ghosts?
Old English þymel "sheath or covering for the thumb," from thuma (see thumb) + -el, suffix used in forming names of instruments (cf. handle). Excrescent -b- began mid-15c. (cf. humble, nimble). Originally of leather, metal ones came into use 17c. Thimblerig, con game played with three thimbles and a pea or button, is attested from 1825 by this name, though references to thimble cheats, probably the same swindle, date back to 1716.
small, bell-shaped implement designed to protect the end of the finger when sewing. Among the earliest known thimbles, dating from before AD 79, were those made of bronze and found at Pompeii and Herculaneum. Modern thimbles are almost exclusively produced in plastic or soft metals. Purely decorative thimbles are produced in an endless variety of materials and forms as collectibles.