A website that is subordinate to another website and hosted in its entirety under that site's domain name.(noun)
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Use "subsite" in a sentence
"Yes, publishers have lots of great unsung content on their sites such as Random House's Word and Film subsite but I hope Bookish brings in real journalists to do a sprucing up of all the material taken from the publishers' sites."
"Visitors to the subsite can print out coupons for weekly deals redeemable at stores."
"In addition, HBO have added a Game of Thrones-centric subsite and forum to their main website and confirmed that a veteran Dexter director, Brian Kirk, will be handling two episodes of the first season."