The word "subsigned" is spelled with two "s" sounds because it is pronounced "sʌbˈsaɪnd." The first "s" sound comes from the prefix "sub-" which means "under." The second "s" sound comes from the root word "sign" which means "to write one's name." When combined, "subsigned" means to sign beneath someone else's signature or to endorse. It is important to spell words correctly to avoid confusion and ensure clear communication.