the stage or period of greatest vigor, strength, success, etc.; prime: the heyday of the vaudeville stars. 2. Archaic. high spirits. Origin of heyday1.
A USB flash drive, also variously known as a USB drive, USB stick, thumb drive, pen drive, jump drive, flash-drive or USB memory, is a data storage device that includes flash memory with an integrated USB interface. USB flash drives are typically removable and rewritable, and physically much smaller than an optical disc.
A pen drive being inserted into a USB port. noun. The definition of a pen drive is small storage device shaped like a pen with built-in data storage that connects to a computer by a USB port. An example of a pen drive is a pen with a hidden USB port for saving data. Noun. (plural pen drives)