greg
n. countable A1 Beginner US //ˈɡɹɛɡ// greg
n. a common short name for a man, usually for someone named Gregory.
n. a masculine given name, typically serving as a diminutive or hypocorism of Gregory.
My friend Greg is coming over for dinner tonight.
After working at the firm for ten years, Greg decided it was time to start his own business.
While his legal documents all listed him as Gregory, he preferred that his colleagues and friends simply call him Greg in all professional and social settings.
Usage
As a proper noun, it is always capitalized.