WOMBA means anything that is awesome. It is usually yelled with excitement and passion and a deep voice. Pronounced "Wom (like "tom")-Buh(like "duh).
"WOOMBBBAAA!" - after winning a basketball game or something
"WOMBBAAA!" - want to feel manly so you say it loudly and deeply.
That was fricking WOMBA! - That was fricking amazing or awesome.
WOMBA. - Hello or hola