Second window

Second window may refer to:


 * broadcast syndication rights for a work following the expiration of first window rights for that work
 * the inter-partes review period for third-party challenge and opposition of a granted patent or trademark
 * a wavelength band or transmission window in fibre-optic communications
 * the period of ischemic preconditioning, starting 24 hours after a coronary occlusion and lasting up to 72 hours, that can limit injuries of a subsequent ischaemia reperfusion in the myocardium