Meaning cool. Antonym is 'anti-lush'. There is a hand symbol that accompanies this term, the symbol for lush is a peace sign with your thumb out as well. The sign for anti-lush is the same thing, just turn your hand upside down, so it looks like an A. Lush has an online symbol.
The new 'fresh'. A go-to word that can be used to describe any noun or verb which the speaker finds particularly rich in flavour, aesthetic or sound. It is used particularly in Jazz, as a tribute to Billy Strayhorn's composition "Lush Life" and the album by John Coltrane of the same name.
"Dude, check out the lush chords that Gamran is layin' down."
"Pretty lush garden you've got here."