This Tagalog slang is from the inversion of the syllables in the word tigas, meaning hard. 

adjective: tough, macho
noun: a man who’s tough, cool

cool, badass, kickass, awesome, thug

Astig ng suot mo, pare!
Your duds are cool, dude!
= What you’re wearing is hip (in a masculine way).

Astig ng dating mo, pare!
You make a cool impression, bro!

ang dalawang astig
the two tough guys
= the two cool guys

ang mga astig ng Maynila
the tough guys of Manila

Sino ang pinaka-astig?
Who’s the toughest and coolest?