Aussie slang
The combination of the terms "cosy " (simular to the adjectives cool, awesome, sick)
"That guy is a cosy ca'nt"
And
"dank" (Adjective meaning good, potent, strong, heavy)
"Man, that was some dank bud"
"Cosy dank" is a super adjective and can be used at any time.
Origins Australia with a influence from New Zealand.
F@#k dude, those sunnies are cosy dank!
Shit yea! Cosy dank!