In the following sentence, which word serves as a definition of 'transient'? 'Her transient thoughts of quitting her dead-end job are fleeting.'

The word 'transient' refers to something that does not last long and is temporary in nature. In the context of the sentence, the phrase 'Her transient thoughts of quitting her dead-end job are fleeting' implies that her thoughts are not stable or enduring; instead, they come and go quickly. The word 'fleeting' captures this essence perfectly, as it directly suggests a brief or momentary quality. Therefore, 'fleeting' serves as the definition of 'transient' by emphasizing the lack of permanence in her thoughts about quitting her job.