From en.wiktionary.org:
[langsam]
** English
[wikipedia]
*** Etymology
Borrowed from [en], a Jewish Ashkenazi surname, from the adjective [de].
*** Proper noun
[s]
1. [en] .
**** Statistics
- According to the 2010 United States Census, _Langsam_ is the 39117 <sup> th </sup> most common surname in the United States, belonging to 563 individuals. _Langsam_ is most common among White (96.98%) individuals.
*** Further reading
- [R:en:DAFN]