Badspot joined my server!

[Zeblote]

um... yes
it's a subdomain of the top-level domain "us"

No, it's a domain

[Ad Bot]

[Foxscotch]

No, it's a domain

"Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs) ... Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites."

"The hierarchy of domains descends from the right to the left label in the name; each label to the left specifies a subdivision, or subdomain of the domain to the right."

so, uh,
yes