(Not really)

Starting the discussion about lunch plans with your coworkers, working to influence the destination and then dropping out at the last minute because you never intended to go.

The region between the balls and the arse-hole; can be an erogenous zone for some.

Girl: 'I was fingering that part between his balls and his arse and there was shit there.'
Everyone listening remained silent but later laughed among themselves:
'Eww! He had a shitty chad.'

When you measure your dick, don't start at the arse-hole and include the chad; you risk getting shit on your measuring tape.

A Chad, in modern internet slang, is generally a sexually active "alpha male". The term has become a slang term across the internet and among adolescents in general to refer to particularly attractive or confident males.

The sticky build up found between the scrotum and arse.

Build up increases when the person doesn't shower or has had a hot sweaty day.

Person 1: Yo Yotty, take a whiff of this.
Person 2: Damn! What the hell is that on your fingers.
Person 1: I haven't showered in days and that's some of the wicked chad I'm brewing from underneath my fat ball sack.

1. Residue of faecal matter; usually situated between arse cheeks after incomplete wiping and can spread to balls.

The smell of chad emanates further and becomes more putrid the riper it gets; annoying all those in close proximity, while the chaded person is often oblivious to their wafting odour. Left unattended the chad will become skid marks.

2. In reference to the male anatomy, it is the space between the anus and the scrotal sac.

The etymology is uncertain as to which definition came first and it's likely the term bifurcated into both definitions after those with chad on their chad created the ambiguity.

i.e. One person telling another the smell of his chad was verging on offensive. Some of those overhearing the complaint went away assuming chad to mean the first definition above, while others assumed it was the second definition.

Differentiation between the two is determined by how chad is used in a sentence.

The girl's first sentence below is rather ambiguous, while it's obvious the guy is referring to his itchy chad (anatomy).

The guy's last sentence below uses both definitions to beautiful effect, respectively.

Both definitions spread like wildfire equally and preference of one definition over the other can be regional.

Globally, most places accept both definitions and the local translation of the English name Chad, all in lower case, is used in many instances. i.e. the term is tsjaad in Dutch, čad in Croatian, csád in Hungarian, etc.

A type of person who is a chatterbox, yet kind and sweet

In reference to the male anatomy, it is the space between the anus and the scrotal sac.

A chad is the area between a guy's asshole and his nut-sack.