The word "unattires" is spelled with the prefix "un-" which negates the verb "attire" meaning to dress. The pronunciation of "unattires" is /ˌʌn.əˈtaɪəz/ where the stress is on the second syllable. The first syllable is pronounced as "un" which sounds like "uhn" and the second syllable is pronounced as "a-tires" where "ti" is pronounced as "tie" and "res" is pronounced as "uhz". The word "unattires" refers to the act of undressing or the state of being without clothing.
The word "unattires" does not have a specific etymology as it is a combination of the prefix "un-" meaning "not" and the noun "attire" which refers to clothing or garments.