R is rumble. A rumble is when they get in a fight with another gang like the Soc's. Ponyboy wanted to beat the Soc's up and be in the rumble so bad he practically begged Darry to let him.
T is for trademark. The greasers trade marker was there hair. To be a greaser you had to have greasy kinda long hair. That was a trademark for them. That's why when Ponyboy had to cut his hair he was kind of upset.
U is for tUff. "Tough" is the same as rough; and "tuff" means cool and sharp. A tuff- looking mustang or tuff record; both is a compliment in there neighborhood.
W is for weapon. There gang doesn't ever use weapons. The only weapons they have ever used is knife. Ponyboy says they always bring knifes or switch blades with them everywhere in there pockets.
Y is for young. Ponyboy just turned 14. The oldest boy, Darry, he is only 20. The boys are so young, yet they struggle with situations which even adults would have difficulty surviving.
Z is for zoo. When Ponyboy got back to school he had to write an essay about anything he wanted and he was going to write something about when he was going to go to the zoo.