Namaste is a Hindi greeting. It is used in initial greeting and can also be used when parting ways, as was used in the episode. It literally means I bow to you, for those who were asking.
Jessibabi-anime_lov said that namaste means hello.
It's great to ask questions, but often times if you read the posts before you, someone already answered it.
*silent* ....pu-chan can still surprise meh e.e...thats y i cam eto thois conclution!!! PU-CHAN ISH POSSESSED!!!!!! yesh its true..or how else can he remmember it D: N SUMTIMES I FORGET PU-CHAN ISH A PUPPET!??! ehH!>?!>?!?!?!? *silent* @.@