The term 'lasting only for a short time' can be described by four words: TRANSIENT (9 letters), MOMENTARY (9 letters), TEMPORARY (9 letters), and EPHEMERAL (9 letters). TRANSIENT means lasting for a very short time, while MOMENTARY implies something that is brief and fleeting. TEMPORARY suggests something that is not permanent, and EPHEMERAL refers to something that is short-lived. All four words describe something that is not meant to last, and are often used to describe things that are fleeting or impermanent.