To be strong and resistant; be sturdily stoic; persist; tough it out: Cook claimed that he was innocent of any wrongdoing and until last week insisted that he would ''gut it out''(1970s+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with gut it out
tough it out. Show pluck and perseverance in the face of opposition or adversity. For example, I know it's hard but we'll just have to gut it out, or His boss has a terrible temper, but Joe is determined to tough it out. The first term dates from the mid-1900s; the variant was first recorded in 1860.