- a contoured holder for the blade of a knife, sword, etc.
- a covering or receptacle resembling this, as the membrane around a muscle, a leaf base enveloping a stem of grass, etc.
- a woman's closefitting dress
- Brit. condom
Origin of sheathMiddle English schethe from Old English sceath, akin to German scheide from Indo-European base an unverified form skei-, to cut, split, divide (from source Classical Latin scire, to know): the earliest form of sheath was probably a split stick