An urge is the feeling to act on something sexual - like, maybe you have a sexual thought and you want to really delve into it... Maybe there's a girl on social media you really wanna check out to see how hot she's looking... Maybe you just wanna flat out fap "so that you can think straight again"... Those are all urges... You should be able to go through your day without thinking anything sexual whatsoever.
Sorry but I must say this. Please do not guess answers. Go read the getting started with nofap. Most people, including me, do not have any urges during flat line. I am yet to experience flatline exit. But my understanding is that Sexual libido returns Fatigue and low energy goes away
"Urge" isn't in the glossary here at NoFap... So you're telling me that's not what it is? What is it then? I'm intrigued...