the.com/shuriken

means A shuriken is a small, sharp throwing weapon — typically a flat metal star or spike — used historically by Japanese warriors as a concealed, hand-thrown projectile.

from Straight from Japanese: shuri (手裏), roughly 'within the hand' or 'palm-hidden,' plus ken (剣), 'blade' or 'sword' — so literally 'hidden hand-blade.' The word names exactly what the thing does: a blade tucked in the palm, ready to fly. The famous star shape is only one variety (the shaken or 'wheel blade'); the older bō shuriken were simple straight spikes. The weapon and its name came west in the 20th century riding the wave of ninja lore, where the spinning star became pop-culture shorthand for stealth itself.