A nickname for marijuana. Someone who likes to talk about marijuana. Also can be someone who like to smoke marijuana. Or just someone who plain straight hates marijuana but likes the name Juana. Juana can also be used in a phrase used in all sorts of ways(1 shown below).
'Juana sucks, man!
wanna go smoke some 'Juana?
a gun usually used and said in Dominican Republic
Yo let me use juana.