The term "be long lived" refers to something or someone that has a long life span. The opposite of this phrase is "be short-lived," which refers to something or someone that has a brief existence or lifespan. Other antonyms for "be long lived" include "be ephemeral," "be transient," and "be fleeting." These words describe something or someone that is short-lived, impermanent, or temporary. While some things may be long-lasting or enduring, others may be fleeting and quickly fade away. Understanding antonyms can help to give a more comprehensive understanding of a word's meaning and context.