Singlet

Singlet may refer to:

• singlet state, in theoretical physics, a quantum state with zero spin
• in spectroscopy, an entity appearing as a single peak; see NMR spectroscopy
• in optics, a single lens element, the building blocks of lens systems; see lens (optics)
• a one-piece collarless garment, also known as a sleeveless shirt or vest
  • wrestling singlet, a one-piece garment specific to wrestling
• BID/60, a British encryption machine

and also :

• Singlet oxygen, the common name used for an excited form of molecular oxygen