Subdomain

noun

noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    A domain or sphere that is part of a larger domain or sphere.

    "As a technical subdomain of biology ecological investigations have evolved from what has been traditionally called natural history."

  2. 2
    A domain name that has been prefaced with additional parts separated with periods. Internet

    "A domain is a subdomain of another domain if it is contained within that domain. This relationship can be tested by seeing if the subdomain's name ends with the containing domain's name. For example, A.B.C.D is a subdomain of B.C.D, C.D, D, and " "."

  3. 3
    An additional part prefaced to a domain name. Internet

    "In en.wiktionary.org, en is a subdomain."

Synonyms

All synonyms
domain nameunqualified hostnameunqualified hostname

Example

More examples

"How do I create a new subdomain?"

Etymology

From sub- + domain.

Related phrases

domain namesecond level domaintop level domain

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.