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1.
When one or both of a person's lungs become coated in cum.
Your sister coughed up a lungnut this morning after deep throating my ejaculating cock.
by fevertree99 June 03, 2010
3 0
 
2.
The lumpiest part of sputum after coughing.
Steve has pneumonia and just coughed up a lungnut.
by Tidal February 05, 2014
0 0