idle
lazy
'Lazy' might fit, also 'foul', or 'icky'.
The 4-letter root word meaning against or opposite is "anti."
Oh, dude, that's easy peasy. The word you're looking for is "show." Like, you know, when you want to display something to the world but you're too lazy to say a longer word. So, yeah, "show" is your go-to 4-letter exhibitionist word.
pass
Dues
care
east
grab
Guts
gnus
left