IPA: //ʌnˈsaɪnd//
KK: /ʌnˈsaɪnd/
Not having a signature or endorsement; also refers to a type of number that is only positive and does not include negative values.
The contract was unsigned, so it was not valid.
Unsigned → It is formed from "un-" (meaning not) and "signed" (from Latin "signare", meaning to mark or sign). The word "unsigned" means not marked or not having a signature.
Think of 'not' ('un-') having a 'mark' or 'signature' ('signare') — that's why unsigned means something that does not have a signature.