When somebody uses the word Cappin’ it simply means that they are lying or not telling truth concerning something.
The idea being that the more the surface area of somebody’s forehead the smarter he is and the opposite is also true that an individual with a smooth cerebrum (no wrinkles) has less surface region and would subsequently be idiotic.
No cap is also a hashtag. it is copied from YoungBoy Never Broke Again viral song that heaps of TikTok clients lip-sync to. It is an expression used by influencers with no particular definition dependent on use its intended.
The urban dictionary uses the word cappin to mean somebody who lies about their social standing. Used in 1980’s to mean somebody who flaunts their possessions yet even acquired by debts.
Nowadays it is used to depict a liar however though actually old its significance is the same.