The origins of Dean St.'s name remain murky. Research shows no one of this name living in the area before J. Wyman Jones came to modernize the area. And it does not appear in the 1867 and even the 1708 Banta farm map.... yet it does appear on the 2nd ward Lydecker map of 1750, but appears only by the 1876 map, when it was already named. A bit of an enigma??
One researcher found that in Old English, the word Dean, or Dene, meant "Valley", especially a narrow or wooded one. 
In the 2003 work by the Englewood Historical Society, Dustin Griffin posits that it could have been named for Gibert Dean, who was residing near here at the newbridge station of Hackensack township in the early 1800's. In the 1870 US Census, he lists his profession as "laborer". And for that reason alone it seems unlikely that this main thorofare is named for him. Moreover it is already called Dean St. in the 1876 maps, but does not yet exist in the 1867 map of the region. 
There are candidates for the name from people living at the time. It turns out that there WAS a Silas Deane, who was a known associate of George Washingtons's, and would have been well known to anyone still alive after the revolution. This seems to be the best candidiate, as other streets were named for revolutionary War heros, or other personalities of the times, like Lafayette.
Further bolstering this argument is the fact that while Dean St. existed in 1876, it was not yet showing on the 1708 Banta farm map of 1708. Nor on the 1867 map of the rehion in the posessson of the Ridgewood Library. Yet it DOES appear on the 2nd ward Lydecker map of 1750 .
- Staff writer. "Dean". definition. Dictionary.com. http://dictionary.reference.com/browse/dean. Retrieved 3/15/2015.
- Griffin et al, Dustin (2003). Englewood: Historical Sketches. Englewood Historical Society. p. 52.
- Lattimer, John MD, ScD (1990). This Was Early Englewood. Englewood Historical Society. p. 278.
- Lattimer, John MD, ScD (1990). This Was Early Englewood. Englewood Historical Society. p. 279.