In Latin American and especially Puerto Rican slang, it's a contraction of "para adelante" or "forward."
Un, dos, tres, un pasito pa' lante Maria! (One, two, three, one little step forward, Maria!) -- Ricky Martin song
The Puerto Rican drag queens in RuPaul's drag race have the motto "echa pa' lante." (Go forward.)
183👍 15👎