In modern slang, "cap" means a
lie or falsehood. To say someone is "capping" means that they are lying or exaggerating.
The use of "cap" in this sense is believed to have originated in the southern United States, particularly in African American communities.
One theory is that it may derive from the word "capping," which in the 1940s was used to
mean "to top" or "to surpass," often in the context of boasting or exaggeration. This evolved into meaning "to
lie" or "to exaggerate" over
time.
The term gained widespread popularity through its use in hip-hop music and social
media in the late 2010s.