Gírias — slang — change from city to city and from one generation to the next. These are the ones you'll hear most:

Gíria	Meaning	Who and where
massa	great, cool	all over, but above all the Northeast and Brasília
maneiro	cool	Rio above all
da hora	cool	São Paulo above all
top	great, excellent	nationwide, all ages
mó	really, so — before a noun or adjective	Rio and São Paulo, informal: mó calor (so hot)
demorou!	you bet! let's do it!	Rio and São Paulo, younger people
valeu	thanks; also bye	nationwide, informal
beleza	OK, sounds good · Beleza? — How's it going?	nationwide, informal

• Mó is short for maior.
• Demorou literally means it took a long time — as in, what are we waiting for? It's the eager answer to an invitation.