What does Den mean?
Den /den/ [1 syll.] as a boys' name is of Old English derivation, and Den means "follower of Dionysius; son of Dennis". Den is a version of Dennis (English, Greek): also variation of Dionysius. Den is also a variation of Dennison (Old English).
How popular is Den?
Den is an uncommonly occurring first name for males but a very prominent last name for all people (#60230 out of 150436, Top 40%). (2000 U.S. Census)
Below is a charted comparison of the popularity of the boy name Den and associated names. Popular variation forms of Den (not in Top 1000) are Denis, Dennie, Dennis (#491 last year), Denny, Deon, Dion and Dionisio. Variants like Dionysus are seldom used. Usage of these boy names reached its peak during the years 1970-1979 (usage of 0.3946%) and is now much lower (usage 0.0727%, down 81.6%), with versions like Dennie, Dennis, Denny, Deon and Dion becoming somewhat outmoded. (Top 1000 Birth Names Records, 2014)
Den is alike in pronunciation to Dain, Dan▼, Dane▲, Dann, Dean▲, Deane, Deen, Deion▼, Dene, Deonn, Deyn, Deyon, Doan, Don▼, Donn▼ and Dunn. Other suggested similar baby names are Ben▼, Dana▼, Dani, De-, Dee▼, Del▼, Des, Dev, Dex, Dino▼, Dom, Ken▼, Len▼, Pen and Ren. These names tend to be more commonly used than Den.