dennis
n. countablen. a common name for a man or a boy. It is used to identify a specific person.
n. a masculine given name of Greek origin, derived from Dionysius. It is used as a proper identifier for a male person.
My friend Dennis is coming over for dinner tonight.
The manager, Dennis, will be happy to assist you with your refund request.
While the name Dennis was exceptionally popular in the mid-twentieth century, its usage has declined in recent decades as naming trends have shifted toward more contemporary choices.
From Middle English Denis, from Old French saint's name Denis, brought to England by Normans; from Latin Dionysius, a masculine name literally meaning “follower of (the wine god) Dionysus”.
As a proper name, it is almost always capitalized and typically used without an article unless referring to a specific person among others with the same name.