Combination word of
Saitama, the
prefecture north of
Tokyo, and
dasai, the
Japanese word for
uncool.
Dasaitama is used to make fun of and put down Saitama because of its
rural and
backwards image in comparison to the
urban Tokyo.
Dasaitama is a nationally well known word because it seems that this wonderful compound word has its roots in the 80's after the tarento Tamori used it to make fun of the prefecture. Of course, most natives don't like the word, but many accept it, some even proudly refer to their home prefecture as Dasaitama despite its negative connotation.
See also Chibaraki.