A more thorough explanation:

Definition: "Under one's hand" refers to a signature that is written by hand, rather than printed or stamped. Example: When signing a legal document, it is important to sign it under one's hand to ensure that it is a valid signature. Explanation: This means that the signature is written by the person themselves, using a pen or other writing instrument. It is considered more authentic and legally binding than a printed or stamped signature, which could be easily replicated by someone else.