The phrase "march cannon's mouth" refers to the act of moving forward despite significant danger or obstacles. While this term might not be commonly used in everyday conversation, there are several other phrases that convey a similar meaning. These include "charging ahead," "pushing through," "braving the storm," "facing the fire," and "giving it your all." Each of these phrases describes the act of moving forward despite the risk of harm or failure. Whether you're facing a difficult task at work or persevering through a challenging personal situation, these phrases can help you stay motivated and focused on your goals.